STATE
OF THE
GREAT LAKES
1997
-------
State
of the
Great Lakes
1997
by
the Governments of
Canada
and
the United States of America
-------
COOPERATING TO IMPLEMENT THE GREAT LAKES WATER QUALITY AGREEMENT
MISE EN OEUVRE DE L'ACCORD SUR LA QUALITE DE L'EAU DBS GRANDS LACS
State of the Great Lakes
1997 - The Year of the Nearshore
Prepared by
Environment Canada
and the
U.S. Environmental Protection Agency
For additional copies please contact:
ENVIRONMENT CANADA
Office of the Regional Science Advisor
867 Lakeshore Road
Burlington, Ontario L7R 4A6
Canada
ISBN 0-662-26003-1
Catalogue No, En.40-11/35-1997E
U.S. ENVIRONMENTAL PROTECTION AGENCY
Great Lakes National Program Office
77 West Jackson Blvd.,
Chicago, Illinois 60604
U.S.A.
EPA905-R-97-013
STATE OF THE GREAT LAKES
1997
-------
Table of Contents
Executive Summary vi
1. Introduction 1
1.1 Background to SOLEC 1
1.2 SOLEC 94 3
1.2.1 Update on Aquatic Community Health Since 1994 5
1.2.1.1 Exotic Species 5
1.2.1.2 Community Structure 5
1.2.1.3 Overall Rating 6
1.2.2 Update on Aquatic Habitat and Wetlands 6
1.2.2.1 Overall Rating 6
1.2.3 Update on Human Health 6
1.2.3.1 Trends in Environmental Levels of Contaminants 6
1.2.3.2 Fish Consumption Advisories 7
1.2.3.3 Contaminant Burdens in Humans 7
1.2.3.4 Overall Rating 7
1.2.4 Update on Toxic Contaminants 7
1.2.4.1 Overall Rating 8
1.2.5 Update on Nutrients 8
1.2.6 Update on Economy 8
1.2.6.1 Overall Rating 9
2. Ecosystem Integrity and Biodiversity: Saving the Pieces 9
2.1 Integrity , 9
2.2 Biodiversity 9
2.3 Sustainability 10
3. State of Information 11
4. Indicators 13
5. The Nearshore 14
5.1 The Nearshore Waters 15
5.1.1 Physically Unique 15
5.1.2 Health of the Nearshore Waters 17
5.1.3 Human Health 24
5.1.4 Overall Rating 25
5.2 The Coastal Wetlands 27
5.2.1 Physically Unique 27
5.2.2 Health of Coastal Wetlands 28
5.2.3 Overall Rating 29
5.3 The Land by the Lakes 30
5.3.1 A Unique and Diverse Landscape 30
5.3.2 The Health of the Land by the Lakes 31
5.3.2.1 Ecoregions 32
5.3.2.2 Ecological Communities 32
5.3.2.3 Lake by Lake Assessment 33
STATE OF THE GREAT LAKES —1997 liii
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6. Stress on the Nearshore 36
6.1 Physical Stressors Including Land Use 36
6.2 Chemical Stressors 39
6.3 Biological Stressors 43
7. Lake by Lake 45
7.1 Lake Superior 46
7.2 Lake Michigan 49
7.3 Lake Huron 51
7.4 Lake Erie 53
7.5 Lake Ontario 55
8. Connecting Channels 57
8.1 St. Marys River 58
8.2 St. Clair River 58
8.3 Lake St. Clair 59
8.4 Detroit River 60
8.5 Niagara River 60
8.6 St. Lawrence River 61
8.7 Common Stressors of the Connecting Channels 61
9. Management Challenges 64
10. Glossary of Terms 71
11. List of Figures and Tables 75
12. Photo Credits 76
13. SOLEC 96 Background Paper Information 76
IV
STATE OF THE GREAT LAKES—1997
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Acknowledgments
The following people have dedicated a great deal of time and effort to the preparation of this report:
Environment Canada United States Environmental Protection Agency
Harvey Shear Kent Fuller
Nancy Stadler-Salt Duane Heaton
Nicole Swerhun Karen Holland
Paul Horvatin
Additionally the following people contributed to the writing of this report:
Victor Cairns, Department of Fisheries and Oceans Canada
Fred Conway, Environment Canada
Ray Hoff, Environment Canada
Rimi Kalinauskas, Environment Canada
Anne Kerr, Environment Canada
Linda Mortsch, Environment Canada
Dale Phenlcie, Council of Great Lakes Industries
The authors of the background papers (and contributors who are too numerous to list here) must
also be recognized for their hard work and for meeting the challenge of writing papers under very
tight deadlines:
Nearshore Waters Murray Charlton, Environment Canada
Thomas Edsall, U.S. Geological Survey
Coastal Wetlands Laurie Maynard, Environment Canada
Douglas Wilcox, U.S. Geological Survey
Land by the Lakes Karen Holland, U.S. Environmental Protection Agency
Ron Reid, Bobolink Enterprises
Impacts of Changing Land Use Victoria Pebbles, Great Lakes Commission
Ray Rivers, Environment Canada
Steve Thorp, Great Lakes Commission
Information & Wendy Leger, Environment Canada
Information Management Rich Greenwood, U.S. Fish & Wildlife Service
And lastly, thanks must go out to the many reviewers of this report.
STATE OF THE GREAT LAKES—1997
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Executive Summary
This report summarizes the state of the Great
Lakes as of the end of 1996. It is based upon
the information contained in five background
papers gathered for and discussed during the
SOLEC '96 conference. The SOLEC process
began with the first conference in 1994 which
addressed the entire Great Lakes ecosystem.
The "State of the Great Lakes 1995" report
was then produced by the Governments of
Canada and the United States of America.
SOLEC 96 focussed its attention on the
nearshore areas as the most heavily impacted,
yet the most productive part of the system. The
background papers which support this report
have been modified based upon input received
during the conference. The background papers
are: Nearshore Waters of the Great Lakes;
Coastal Wetlands of the Great Lakes; Land by
the Lakes - Nearshore Terrestrial Ecosystems;
Impacts of Changing Land Use; Information
and Information Management.
To provide a systematic basis for discussion,
the background papers addressed three con-
centric geographic zones plus two other topics.
Because of the magnitude of the impacts of
changing land use, land use was given special
attention. Additionally, because of the impor-
tance of information and information manage-
ment, and because of the rapid changes in
electronic data systems, a separate paper on
this topic was prepared.
SOLEC 94 Update
The first State of the Great Lakes report pro-
vided an overall view of the state of the Great
Lakes ecosystem at the end of 1994. There
are no major changes to report regarding the
conclusions made. This is not surprising, since
it often takes many years of observation to
note changes or to reach conclusions regard-
ing the response of an ecosystem to changes
in stress, especially a system as large as the
Great Lakes.
While the overall evaluation of aquatic commu-
nity health as mixed/improving has not
changed, there have been some notable
changes reported in the status of both exotic
species and community structure:
Ruffe (fish) has now extended its range from
Lake Superior to northern Lake Huron and
poses a threat to native species, especially
perch.
The round goby (fish) is expanding its range
throughout the Great Lakes. Only Lake Ontario
has not had a range extension reported.
The lake trout population in Lake Superior has
recovered to the extent that stocking has been
suspended.
Lake Erie remains a very stressed ecosystem.
Fish populations continue to decline in produc-
tivity.
Lake trout are now showing increasing natural
reproduction in Lake Ontario for the first time in
50 years. A recent sighting of a deepwater
sculpin (Myoxocephalus quadricornis) indicates
that this formerly "extirpated" native species
may be recovering.
Fish consumption advisories are in effect in
many parts of the Great Lakes basin. However,
according to the 1997 Guide to Eating Ontario
Sport Fish, contaminants found in fish are
continuing to decline as a result of the bans
and restrictions that have been placed on
chemical substances such as DDT, PCBs,
mirex, toxaphene, chlordane and dieldrin.
Based on studies of blood samples and breast
milk samples, levels of bioaccumulating con-
taminants in tissues of human residents of the
Great Lakes basin are similar to those of other
regions in the temperate zone, and are lower
than those in the far North and Arctic. No
significant changes have been reported since
1994.
Urban sprawl that had slowed down as a result
of the recession can be expected to accelerate
with the improvement in general economic
conditions in both Canada and the U.S. The
VI
STATE OF THE GREAT LAKES
199
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expected cessation of migration from the basin
and a return to population growth is expected
to result in accelerated sprawl.
SOLEC 96
Nearshore Waters
The status of the nearshore waters was evalu-
ated using a number of desired outcomes
encompassing the health of humans and of
fish and wildlife, as well as the stresses posed
by nutrients and contaminants. The ratings of
the indicators for the nearshore indicates that
the nearshore aquatic environment is mixed/
improving.
Coastal Wetlands
The overall state of coastal wetlands in the
Great Lakes ecosystem is known only in part
and that is why an overall rating could not be
given. There is no inventory or evaluation
system in place for the majority of coastal
wetlands. The general location of coastal
wetlands is known from remote sensing and
aerial photography, but there is no commonly
accepted system of classification nor is there
systematic information on their quality, rate of
loss or rate of degradation. Much is known
about the stressors that degrade wetlands, and
the condition of some local areas have been
relatively well studied, but it is not possible at
this time to provide a comprehensive review of
the state of Great Lakes coastal wetlands.
Nevertheless, several desired outcomes for the
health of fish and wildlife populations, as well
as the status of the stressors on wetlands were
evaluated. Generally the indicators were rated
as poor to mixed/deteriorating.
Land by the Lakes
The health of the land by the lakes, nearshore
terrestrial ecosystems, is degrading throughout
the Great Lakes. To reach this conclusion, the
nearshore terrestrial environment was viewed
from three perspectives: the ecoregions within
the Great Lakes basin, the special ecological
communities along the lakeshore, and the
status of individual lakes. A letter grade from
W through "F" indicates the quality of the
shorelines of 17 ecoregions and 12 special
ecological communities, whereas a scale from
"good" to "poor" characterizes four elements
regarding the status of individual lakes.
The health of 8 of the 17 Great Lakes
ecoregions has been rated as "A or B" indicat-
ing a relatively good condition, with either slight
or no signs of deterioration, while the other 9
ecoregions have been rated as moderately to
severely degrading, and were rated "C or D".
There are 12 special ecological communities
around the Great Lakes shoreline, recognized
as such because of their unique vegetation
and physical structure. Of these 12, only 2
rated a "B" indicating relatively good health,
while the remaining 10 rated a "C through F"
indicating moderate to severe degradation.
On a Lake-by-Lake basis, Lake Superior's
nearshore lands rated the highest (good or
mixed/improving) in terms of ecosystem health,
while Lakes Michigan, Erie and Ontario were
rated much lower (poor or mixed/deteriorating).
Lake Huron was rated in the middle, with some
indicators showing improvement, and others
showing deterioration.
Land Use
As evidenced by the state of ecosystem health
within the three geographical components of
the Great Lakes nearshore, the nearshore
ecosystem continues to be stressed by human
activity. In particular, industrial, commercial,
residential, agricultural, and transportation-
related activities all have specific and cumula-
tive impacts on the Great Lakes, their tributary
waters, and nearshore areas. Because of their
unique and sensitive environments, and their
proximity to development, Great Lakes
nearshore areas bear the brunt of a dispropor-
tionate amount of environmental burden
caused by human activity. Efficient urban
development, protection of human health, and
protection of resource health were rated using
36 indicators. Most of these indicators were
rated as poor, mixed and deteriorating, or
mixed and stable, indicating that land use
STATE OF THE GREAT LAKES —1997
VII
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practices remain a major source of stress to
the Lakes.
Information and Information Management
Timely access to reliable data is critical for
determining not only the past and current state
of nearshore ecosystems, but also for defining
and achieving future ecosystem management
goals. Data have been collected and analyzed
in the Great Lakes for many years by a variety
of organizations, for a variety of purposes. A
large amount of information has been gathered
in response to the Great Lakes Water Quality
Agreement over a period of decades and
represents an excellent database for the deep
water areas. However, much of that informa-
tion is limited to water quality of offshore areas
and contaminants in fish which spend most of
their lives in offshore areas.
Information on nearshore areas is far
consistent since it has been gathered with
more of a local focus and nearshore areas vary
considerably from place to place. Data have
generally been collected for limited purposes
on an as-needed basis by individual agencies.
The value of such data in system-wide assess-
ments is questionable. As a result of these
limitations, the state of information manage-
ment based on i) data coverage, ii) data time
frames, iii) data applicability to the nearshore,
and iv) data usability were all rated as fair.
Management Challenges
The fundamental challenge for managers and
decision makers is to understand that the
nearshore is an ecosystem and to obtain
enough relevant information to make informed
decisions. Although the ecosystem is complex,
there is an urgent need to agree upon the
present state, desired states, and key steps
needed to attain what is desired. Without this,
it is difficult to provide rational decision making
or to measure progress.
The development of community-based Reme-
dial Action Plans (RAPs) for Areas of Concern,
Lakewide Management Plans (LaMPs), Fisher-
ies Management Plans, and various species
recovery plans provides an opportunity to
involve the necessary interest groups and to
develop practical plans; but these planning
mechanisms have yet to reach full potential.
There are also specific challenges that need to
be met in the next two years:
Information management
The challenge is to develop a common set of
indicators and then to bring together available
information on the state of the nearshore
ecosystem into accessible formats and sys-
tems, including Geographic Information Sys-
tems.
Integration of programs
The challenge is to integrate the concepts of
biodiversity and habitat into existing programs
that, traditionally, are devoted to pollution
control or natural resource management for
harvest.
Integrative management
The challenge is to integrate LaMPs, RAPs,
fisheries management plans, and other plan-
ning activities so that they become fully viable
management mechanisms, useful for decision
makers throughout the Great Lakes basin
ecosystem in taking action and assessing
results.
Efficient land use
The challenge is to find ways to promote land
use that is both efficient and protective of high-
value habitat.
Priority areas
The challenge is to identify areas of unusual
importance to the health and integrity of the
Great Lakes ecosystem for priority attention.
Indicators
The challenge is to develop easily understood
agreed-upon indicators to support an under-
standing of the state of the system and to
obtain widespread agreement on what needs
to be done to measure progress.
VIII
STATE OF THE GREAT LAKES—1997
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STATE OF THE GREAT LAKES
I. Introduction
LI Background to SOLEC
The Great Lakes represent the largest single
reservoir of fresh water on the surface of
the earth, excluding the polar ice caps. The
Great Lakes basin ecosystem spans 9° of
latitude and 19° of longitude, and lies halfway
between the equator and the North Pole (Fig-
ure 1). The basin includes the Lakes them-
selves and over 760,000 square kilometers
(295,000 square miles) of land that drains into
them (Figure 2). The governments of Canada
and of the United States of America have long
recognized the value of the Great Lakes as an
important natural resource and have worked
cooperatively for decades to manage the Great
Lakes ecosystem.
In 1995 the governments of the United States
and of Canada, Parties to the Great Lakes
Water Quality Agreement (GLWQA), released
the first of a series of biennial State of the
Location of the
Great Lakes Basin Ecosystem
'f.' ,{,*'7 Great Lakes Basin Ecosystem
Figure I. Location of the Great Lakes Basin Ecosystem
Source: Edsall, T. and M. Charlton. 1997. Nearshore Waters of the Great Lakes. (SOLEC 96 Background Paper)
STATE OF THE GREAT LAKES — 1997
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ONTARIO
Dulutli
N
MINNESOTA l,
; WISCONSIN (
Credit Say
ILLINOIS ' INDIANA
OHIO
-75 0
300 km
Great Lakes Profile
Dulutti Chicago
? f
Lake Superior \ )
St. Marys River
(Soo Locks)
Straits of
Mackinac
St. Clair River
Lake St. Ciair
Detroit River
Lake Michigan
SEA LEVEL
244m
NOTE : 1. The profile Is taken along the long axes of the lakes.
2, The vertical exaggeration is 2000 times.
3. Lake surface elevations are above sea level, and
maximum depths are below lake surface level.
Figure 1. The Great Lakes Basin
Source: Environment Canada and U.S. Environmental Protection Agency. 1995. State of the Great Lakes 1995.
STATE OF THE GREAT LAKES—1997
-------
Great Lakes reports. It summarized the overall
health of the Great Lakes ecosystem at the
end of 1994. The 1997 State of the Great
Lakes report, with its associated background
papers, narrows the scope to summarize the
condition of the nearshore ecosystem as
observed at the end of 1996 and gives a
limited update on the subjects addressed in the
first report.
For both reports, information was gathered,
discussed, and reviewed during one in a series
of biennial conferences hosted by Environment
Canada and the U.S. Environmental Protection
Agency. These conferences are known as
SOLEC (State of the Lakes Ecosystem Confer-
ence). The second conference, SOLEC 96,
was held in November 1996 and provided a
framework for this 1997 report.
The purpose of the conferences and the re-
ports is to provide stakeholders, including
policy-makers, throughout the basin with
information to support better decisions on
issues that will have an impact on the Great
Lakes ecosystem. The conferences give
stakeholders an opportunity to exchange their
knowledge, experiences, and perspectives
regarding the health of the ecosystem. The
intent of the Parties is to deliver a binational
science-based review of the state of the Great
Lakes basin ecosystem, without assessing
agency programs. The conferences and the
reports also reflect the governments' ongoing
commitment to improve their understanding of
the complex ecological relationships that
constitute the system. Accurately assessing
the health of an ecosystem of this size de-
pends on the cooperation of stakeholders
throughout the basin.
Just as no single agency can accurately as-
sess the health of such a large ecosystem, no
single report can cover all the complexities of
the Great Lakes ecosystem or include the vast
amount of related information that is gathered
every year. However, to provide structure for
the conferences and the 1995 report, and to
touch on as many aspects of the ecosystem as
possible, the organizers used the three-level
framework shown in Figure 3. We have contin-
ued using this framework for this report as well.
The top level consists of the living components
of the system, both the health of the human
components and the health of the ecosystem.
The middle level consists of the environmental
aspects of the system, both supporting factors
(positive) and stressors (negative). The lower
level consists of the many sources of
stressors. Programs to deal with problems in
the system can be envisioned as another level,
but are not included in these conferences or
reports. Although programs are very important,
they are a separate matter to be evaluated and
discussed in other reporting vehicles of the
Parties.
This report draws upon information from five
background papers written for the 1996 confer-
ence:
Nearshore Waters of the Great Lakes
Coastal Wetlands of the Great Lakes
Land by the Lakes: Nearshore Terrestrial
Ecosystems
Impacts of Changing Land Use
Information and Information Management
Land use is by far the largest source of stress
in the system and warranted special attention.
Additionally, a separate paper was prepared on
information and information management
because of their importance and the rapid
changes in electronic data systems.
1.2 SOLEC 94
The first State of the Great Lakes report pro-
vided an overall view of the state of the Great
Lakes ecosystem at the end of 1994 and drew
the following conclusions:
* Loss of aquatic habitat has been
devastating and has been largely ignored [up
to that time] by government programs focused
on contaminants.
STATE OF THE GREAT LAKES —1997
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PRIMARY ECOSYSTEM EFFECTS, STRESSORS, AND SOURCES
ECOLOGICAL INTEGRITY & BENEFITS
Ecological Health
Self-Sustaining Communities of Native Species
Genetic Diversity
Productivity
Unimpaired Reproduction
Healthy Organisms
Human Health and Welfare
Healthy Humans
Reduced Exposure and Risk
Quality of Life
Swim
Fish and Hunt
Eat Fish and Game
Drink Water
Aesthetic Enjoyment
Satisfaction/Feeling of Well-being
Economic Benefit
Recreation Industry
Tourism Industry
Commercial Fishery
Reduced Health Costs
KEY STRESSORS
Chemical
Toxic Contamination
Excess Nutrients
Biological
Excess Competition
Pathogens
Exotic Species
Genetic Loss
Population Disruption
Sedimentation
Habitat Access Loss
Habitat Degradation or Loss
Hydroiogic Modification
ECOLOGICAL
INTEGRITY AND
BENEFITS
Land | Air.
Harvest Oevaiopment; Entiss
or I 1 Erosion,
Stocking 8 Runoff Deposition
SOCIAL
VALUES
BEHAVIOR
INSTITUTIONS
&
ORGANIZATIONS
LAWS
a
POLICIES
PROGRAMS
FACTOHS
THAT
STIMULATE
OR LIMIT
STRESSORS
Figure 3. Conceptual Model of the Relationships Between Ecosystem Health, Stressors, and
Sources of Stress
Source: Great Lakes National Programs Office, U.S. EPA
• Loss of native species has been equally
devastating, with a collateral loss of biological
diversity among and within the remaining
species and populations.
• Invasions of non-native species have had
major impacts on ecosystem integrity.
Contaminant concentrations in fish and
wildlife, as well as in sediments, have declined
dramatically since the early 1970s, but are still
a problem in some areas.
The present phosphorus control
strategies have attained targets.
The health of humans living in the Great
Lakes basin is no worse than the health of
those living in other industrialized areas and is
certainly better than in most countries in the
world.
» Hormone disruption is an emerging issue
that needs to be researched and monitored.
* There is a global component to
contamination due to long-range atmospheric
transportation and deposition of pollutants,
which will make virtual elimination of
contaminants from the ecosystem very difficult.
STATE OF THE GREAT LAKES—1997
-------
* The composition of the food chain is
important in the movement of contaminants
within the ecosystem (changes to the food
chain affect contaminant movement).
• The maintenance of a healthy economy
is essential to restoration of the Great Lakes,
and in the future, economics must be assessed
along with ecosystem stressors.
There are no major changes regarding these
conclusions. This is not surprising, since it
often takes many years of observation to note
changes or to reach conclusions regarding an
ecosystem's response to changes in stress,
especially a system as large as the Great
Lakes. An update on the states of ecosystem
stressors and ecosystem health first evaluated
in the background papers for SOLEC 94
follows.
1.2.1 Update on Aquatic
Community Health Since 1994
1.2.1.1 Exotic Species
Zebra mussels. Range extensions of zebra
and quagga mussels are continuing. In
Lake Erie, their distribution has now
extended to include soft sediments and
vegetation. Colonization of deep-water
sediments by quagga mussels appears to
be having a negative impact on the native
freshwater invertebrate Diporeia, which is
a major component of the foodchain.
Ruffe, Ruffe (fish) have now extended their
range from Lake Superior to Lake Huron
and pose a threat to native species,
especially perch.
Goby. Round goby (fish) are expanding their
range throughout the Great Lakes,
except in Lake Ontario. The species has
been found in eastern Lake Erie and has
become more abundant in central basin
tributaries on the south shore of Lake
Erie. Part of the goby's diet consists of
zebra mussels, but its impact on native
species is unknown.
Sea lamprey. Sea lamprey in northern Lake
Huron are increasing in abundance.
Inability to control sea lamprey in the St.
Marys River seems to be a major factor
in this population increase.
1.2.1.2 Community Structure
Lake Superior. The lake trout population in
Lake Superior has recovered to the
extent that stocking has been suspended.
Lake Michigan. Yellow perch continue to have
problems and are in decline.
Lake Huron. The presence of ruffe has been
confirmed in northern sections, at Alpena,
Michigan.
late Erie. Lake Erie remains a very stressed
ecosystem. Since 1990, walleye, smelt,
and yellow perch populations have been
declining largely as a result of decreasing
productivity caused by zebra mussels
and phosphorus control. Recent
information has shown a possible
recovery in yellow perch and walleye.
Zebra mussel densities continue to
increase lakewide. The unexpected
finding of zebra mussels in soft
sediments and vegetation means that
zebra mussels are likely to continue
increasing. The effects of zebra mussels
in the Detroit River, Lake St. Clair, and
Lake Erie have resulted in greatly
improved water clarity in some nearshore
areas. Associated with these elevated
levels of zebra mussels in Lake Erie is
the presence of summer blooms of blue-
green algae, which are causing problems
for water supplies. Finally, recent
increases in round goby and the arrival of
ruffe in Lake Huron, and their impending
arrival into Lake Erie in the near future,
STATE OF THE GREAT LAKES—1997
-------
create potential for more disruption of
aquatic community structure.
Lake Ontario, The Lake Ontario ecosystem is
experiencing a dramatic decline in
productivity compared with its status in
the seventies and eighties when levels of
phosphorus were significantly higher as a
result of human sources. Quantities of
alewife (the principal prey for salmon and
trout) continue to be lower than in the
previous two decades. Decreasing
nutrient loading from Lake Erie (due to
reductions in phosphorus loading and the
effects of zebra mussels) has contributed
to the decline of alewife. On a positive
note, lake trout are now showing
increasing natural reproduction in Lake
Ontario for the first time in 50 years. A
recent sighting of a deepwater sculpin
(Myoxocephalus quadricomis) indicates
that this formerly "extirpated" native
species may be recovering.
1.2.1.3 Overall Rating
While the overall evaluation of aquatic
community health as mixed/improving has not
changed, some notable changes have
occurred in the status of both exotic species
and community structure as stated above.
1.2.2 Update on Aquatic Habitat
and Wetlands
The authors of the SOLEC 94 paper "Aquatic
Habitat and Wetlands in the Great Lakes"
believe that there has been little, if any,
recovery in the status of these two features in
the Great Lakes, with the exception of
improvements in some Areas of Concern
(AOCs). On the positive side, habitat has
gained wider support as an issue needing
attention, and is becoming important to more
agencies and organizations.
The types of inventories and assessments
proposed in the 1994 paper have not been
undertaken. As a result, current and adequate
trend information to measure gains or losses is
not available. The authors do not know
whether the limited restoration effects in AOCs
and elsewhere are beginning to balance
continuing losses. It appears that losses
continue to substantially exceed gains.
1.2.2.1 Overall Rating
The overall rating for aquatic habitat and
wetlands remains poor.
1.2.3 Update on Human Health
1.2.3.1 Trends in Environmental Levels
of Contaminants
Contaminants. There is no evidence, over the
past five years, of dramatic shifts in levels
or types of bioaccumulating contaminants
in tissues of residents of the Great Lakes
basin. However, the levels of such
contaminants in the tissues of people
eating large amounts of Great Lakes fish
continue to be several fold higher than in
people who do not eat such fish.
Beach closings. Available statistics indicate
persistent bacterial contamination on
many beaches in the Great Lakes basin,
especially in late summer. There are not
enough studies of illnesses related to
recreational use of Great Lakes waters to
draw any conclusions regarding recent
trends.
Drinking water. Outbreaks of cryptosporidiosis
in several municipalities in the Great
Lakes basin due to contaminated drinking
water indicate that infectious diseases
can still pose serious problems. However,
treated drinking water from the Great
STATE OF THE GREAT LAKES—1997
-------
Lakes continues to provide an excellent
source of drinking water.
1.2,3,2 Fish Consumption Advisories
Advisories to restrict consumption of fish
because of bioaccumulating contaminants are
in effect in many parts of the Great Lakes
basin. However, according to the Guide to
Eating Ontario Sport Fish, released on March
7, 1997 by the Ministry of Environment and
Energy, Ontario fish are becoming safer to eat.
The guide notes that most chlorinated
contaminants found in fish are continuing to
decline as a result of the bans and restrictions
on chemical substances such as DDT, RGBs,
mirex, toxaphene, chlordane, and dieldrin. In
the Great Lakes, sampling showed that PCB
(polychlorinated biphenyl) levels in Lake Huron
salmon and trout are generally declining. In
Lake Ontario, PCB levels in salmon and trout
are slowly declining, resulting in some less
restrictive advisories. For Lake Superior,
however, toxaphene is still a major
contaminant causing consumption restrictions,
especially of lake trout. Contaminant levels
remain low in most Lake Erie fish.
1.2.3.3 Contaminant Burdens in Humans
Studies of blood and breast milk samples show
that levels of bioaccumulating contaminants in
tissues of residents of the Great Lakes basin
are similar to those in other regions in the
temperate zone, and are lower than those in
the far North and Arctic. No significant changes
have been reported since 1994. Results of the
Great Lakes human health effects research
programs of the Agency for Toxic Substances
and Disease Registry (ATSDR) and of Health
Canada have shown an association between
the consumption of contaminated Great Lakes
fish and body burdens of persistent toxic
substances (PTSs) such as PCBs, dioxins,
chlorinated pesticides, and mercury. Here are
some other findings of the programs:
« Susceptible populations included Native
Americans/First Nations, sport anglers, elderly
people, pregnant women, fetuses and nursing
infants of mothers who consumed
contaminated Great Lakes fish.
* A significant trend of increasing body
burden was associated with increased fish
consumption.
• Anglers consumed two to three times
more fish than did the general population.
Levels of contaminants in some Great
Lakes fish were above the advisory limits set
by the state and federal governments.
Individuals who consumed Great Lakes
sport fish for more than 15 years had
contaminant levels in blood that were two to
four times higher than non-fish eaters.
In general, men consumed more fish than
women did, and women consumed Great
Lakes fish during most of their reproductive
years.
1.2.3.4 Overall Rating
As in 1994, on the basis of the available limited
information, the state of human health in the
Great Lakes basin, as reflected by human
exposure to persistent toxic substances, has
been rated as mixedimproving.
1.2.4 Update on Toxic
Contaminants
The most recent analysis of temporal trends in
contaminant data in fish communities indicates
that the long-term decline in contaminant levels
continues, although at slower rates than in the
past. However, as reported in the results of the
1996 "Workshop on Toxaphene in the Great
Lakes: Concentrations, Trends and Pathways,"
STATE OF THE GREAT LAKES —1997
-------
sponsored by U.S. Environmental Protection
Agency, toxaphene concentrations in Lake
Superior lake trout are the highest in the Great
Lakes and have not decreased significantly. An
overall slower decrease of those
concentrations in Lake Superior is to be
expected because of lake processes such as
low sedimentation rates and long water-
retention time, but the lack of decrease
remains a puzzle that calls for further work.
1.2.4,1 Overall Rating
The overall rating for toxic contaminants in the
Great Lakes remains mixed/improving.
1.2.5 Update on Nutrients
The authors of the paper on nutrients have
reviewed the data since 1994 and have
concluded that no appreciable change has
occurred in the nutrient status of the Lakes and
that the rating remains good in terms of
achieving the targets for phosphorus reduction
in the GLWQA.
1.2.6 Update on Economy
The Great Lakes basin economy continues to
grow and adapt to the continental and global
marketplace. The largest bilateral trade
relationship in the world is concentrated in the
basin and it also is expanding. This hub of
economic activity is characterized and
supported by strong resource, product and
policy linkages. Recent employment trends
have varied between the two sides of the
basin; Canadian unemploment has remained
relatively high, whereas U.S. job growth has
been strong. Industrial restructuring, which has
been underway since the 1980s, continues to
mold the basin's prominent manufacturing
sector through modernization of equipment
and facilities making it more productive but
with fewer workers. The long-term shift to the
"service and information economy" will
continue as business and personal services
develop new markets and gravitate to growing
metropolitan areas.
Urban sprawl in the Great Lakes basin and its
associated environmental and socio-economic
poblems continues. In some metropolitan
areas within the U.S. portion of the basin,
sprawling urban land uses consumed land at
about ten times the rate of population growth
during the past two decades. Even in cases
where population growth has not occurred,
additional land is still being rapidly consumed
for urban uses. While the most visible form of
sprawl continues at the outer edges of
metropolitan areas, rapid land development is
occurring in communities of all sizes including
recreational development far from urban
centers, especially along the lakeshores. The
irreversible loss of farmland and natural habitat
as a consequence of sprawl will continue until
more efficient land-use practices are
implemented. Urban revitalization efforts
underway or planned including the cleanup and
redevelopment of former factories,
neighborhood improvements and targeted
support for business expansion can make a
difference for these central city places.
Pollution prevention has been enthusiastically
accepted by many as the preferred approach
to environmental management. However, the
success of voluntary pollution-prevention
programs is built upon on the foundation of a
sound regulatory framework. Without a strong
regulatory structure there is less incentive to
implement new pollution-prevention activities.
Those who provide pollution-prevention
technical assistance often find businesses
open to voluntary solutions to achieve
environmental objectives required by
regulations. Businesses are also increasingly
receptive to the message that pollution
prevention will improve their bottom line.
Acceptance and advancement of pollution
prevention continues.
STATE OF THE GREAT LAKES—1997
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1.2.6.1 Overall Rating
No change has occurred in the ratings of the
ten indicators used in 1994; four indicators
were rated as mixed/improving, four as mixed/
deteriorating, and two as poor.
2. Ecosystem Integrity and
Biodiversity: Saving the
Pieces
The state of the Lakes can be expressed in
many ways, but a fundamental beginning
point is the health of the ecosystem in terms of
its integrity. The stated purpose of the U.S./
Canada GLWQA is to restore and maintain the
chemical, physical, and biological integrity of
the waters of the Great Lakes basin
ecosystem.
2.1 Integrity
"Integrity" is not specifically defined in the
Agreement, but is understood to include the
health of the biological populations and
interactive communities of the ecosystem and
their ability to withstand stress or adapt to it.
Ecosystem integrity includes the good health of
living things, the ability of systems to self-
organize, and a physical and chemical
environment that supports good health.
An important part of ecosystem integrity is
genetic diversity. Ecological communities are
dynamic and exist within ranges of conditions
that occur as a result of natural forces.
Communities exist in balance with these
natural conditions, and their composition
changes throughout various states that tend
toward stability and increasingly complex
interrelationships. Mature communities are
relatively stable, compared to younger
communities, and contain proportionately more
organisms that take a long time to complete
their life cycles. These communities also have
more specialized and demanding habitat
requirements.
The Great Lakes ecosystem, although subject
to natural disturbances, was relatively mature
and stable before the arrival of European
settlers. Some stable communities of
organisms have become rare because they are
sensitive to human exploitation of the fisheries
and landscape (for example, those uniquely
associated with old growth forests or
undisturbed wetlands). Part of the challenge of
protecting the ecosystem is to maintain the full
spectrum of all remaining species and
ecological communities.
Another important aspect of ecosystem
integrity is resiliency, or the ability of healthy
systems to self-organize and recover from
stress or disruption. In individual organisms
this is known as "homeostasis": the tendency
to maintain, or the maintenance of, normal,
internal stability by coordinated responses of
the organ systems that automatically
compensate for environmental changes. A
similar process takes place in ecosystems as a
result of interactions between component
parts.
2.2 Biodiversity
Resiliency is also an important aspect of
biodiversity. It is the diversity of genetic traits
within and among species that enables
ecosystems to survive and prosper, even
STATE OF THE GREAT LAKES —1997
-------
though challenged by changing conditions. The
native species and living communities contain
within their genetic makeup the "memory" of
conditions over thousands of years, in which
they have survived in the Great Lakes basin.
Ecosystems are dynamic in time scales
measured from minutes to millennia, and
continue to change and evolve. However, the
speed of changes caused by unchecked
human activity far exceeds the changes that
occur naturally and does not give the system
time to recover or organisms time to adapt or
evolve.
As a result, ecosystem integrity can not be
attained by simply "letting nature take its
course". What is needed, in addition to
managing future human impact, is to save the
remaining pieces of the system to ensure that
they are not lost, and to provide conditions that
allow recovery of the ecosystem. This would
include prudent human intervention to facilitate
recolonization by native organisms and
reestablishment of healthy communities of
native organisms. In this way ecosystem
integrity can be restored and maintained.
Much of the Great Lakes basin ecosystem has
been permanently altered, but viable remnants
of most of the biological components remain. It
is the native plants and other living
communities that provide the best means of
attaining ecosystem integrity and sustainability.
Although any miscellaneous degraded
assemblage of organisms would probably
begin to evolve into new stable communities
over tens or hundreds of thousands of years,
we do not have that amount of time available.
It has been suggested that altered and
reorganized ecosystems may be just as
healthy as the original systems and that
ecosystem outcomes can be selected by
managers or public opinion. However, because
the system is so complex, it is not possible to
predict outcomes and because new species
assemblages have not had time to evolve into
functioning communities, they tend not to make
full use of all available habitats, not to be able to
tolerate the full range of natural conditions
which occur over time, and to be unstable.
Given these circumstances, the prudent choice
appears to be management toward a goal of
protecting and restoring the full range of
ecosystems that existed at the time of
European settlement.
Protection of high-quality areas that contain
viable populations of species and/or
communities that are rare or sensitive to
human disturbance plays an important role in
restoring and maintaining integrity and
sustainability. This function includes protecting
habitat necessary for all life stages of all
species. Sufficient habitat and biodiversity
must be protected to ensure survival in the
event of catastrophic change in any one area.
Protection of viable populations and communi-
ties that represent the full range of nearshore
ecosystems throughout the basin is essential.
This cannot be accomplished by preserving a
few ecological zoos containing representative
samples. Protection must be given to fully
functioning ecosystems throughout the basin.
Living communities are complexes of thou-
sands of interacting species including organ-
isms such as bacteria, fungi, and nematodes.
Another aspect of maintaining integrity is
preserving critical habitat. While exact defini-
tion or identification of critical habitat remains
elusive, it is believed that some habitat is
essential for survival of various species and
genetic stocks or strains within species. Critical
habitat is often associated with reproduction
and protection of early life stages, but it can
apply to all life stages, including migration.
2.3 Sustainability
Sustainable development is an important
concept related to ecosystem integrity. Sus-
tainable development seeks to meet the
present needs of society without compromising
the ability of future generations to meet their
10
STATE OF THE GREAT LAKES—1997
-------
own needs. As a society, we are still falling far
short of this goal since we continue to deplete
our non-renewable resources and spend our
ecological capital" by destroying unique habi-
tats and biodiversity.
Every human society must solve and continue
to solve the basic economic problems of pro-
ducing the goods people need or want and
distributing them where and when they are
desired. For development to be ecologically
sustainable, the knowledge gained from accu-
mulated ecological insights into the impacts of
human activities on the health and functioning
of ecosystems must be fed back into the
development process and be used to adjust
those activities to protect the health and func-
tioning of ecosystems.
Sustainable development is a direction toward
an economy developed by technologies, land-
use practices, laws, and institutions that take
account of ecological understanding. The great
challenge is to create ways of life and commu-
nities within which we humans prosper while
our actions restore the natural life support
system upon which all life and prosperity
depends.
SOLEC 96 focused on two ecosystem integrity
aspects of sustainability; (1) human use and
economic development of the ecosystem
should be sustainable in the long term; and (2)
biological communities should be self-sustain-
ing with minimal (or zero) human assistance.
Ecosystem integrity is measured both in terms
of biological integrity and in terms of human
health. Human health aspects of ecosystem
integrity are difficult to assess because of the
multiplicity of factors affecting human health.
As reported in SOLEC 94, some direct evi-
dence exists of human health effects resulting
from exposure to pathogens and to persistent
bioaccumulative toxic contaminants, but most
information about human health relates to
exposure to health risks.
3. State of Information
In order to report on the state of the Great
Lakes ecosystem, we need to look at the
state of available information itself. For SOLEC
96, the authors of a background paper exam-
ined two aspects: the availability of information
on the condition of the Lakes; and the state of
the databases themselves in terms of what
exists and who is maintaining them. A full
presentation is contained in the background
paper Information and Information Manage-
ment."
Timely access to reliable data is critical for not
only determining the past and current state of
nearshore ecosystems, but also defining and
achieving future ecosystem management
goals. Data have been collected and analyzed
in the Great Lakes for many years by a variety
of organizations, for a variety of purposes. A
large amount of information has been gathered
in response to the Great Lakes Water Quality
Agreement over a period of decades and
represents an excellent database for the deep-
water areas. Much of that information, how-
ever, is limited to the water quality of offshore
areas and contaminants in fish that spend
most of their lives in offshore areas.
Information on nearshore areas is far less
consistent since it has been gathered with a
local focus, and nearshore areas vary consid-
erably from place to place. The overall conclu-
sion from the SOLEC 96 background papers
and conference discussions is that there are
no widely accepted indicators for measuring
the state of the nearshore. Data have generally
been collected for limited purposes on an as-
needed basis by individual agencies, and their
value in system-wide assessments is question-
able. The conference sponsors have accepted
this finding; identifying indicators for the
nearshore areas will be a major theme for the
1998 conference.
One significant challenge is associated with the
use of Great Lakes ecosystem health indica-
STATE OF THE GREAT LAKES —1997
11
-------
tors: the sheer size of the basin and associated
resources required to support long-term data
collection efforts make it difficult to keep eco-
system health information up to date. In fact,
there are only a few data sets that cover the
entire Great Lakes shoreline.
Binational activities carried out under the Great
Lakes Water Quality Agreement (Lakewide
Management Plans, Great Lakes International
Surveillance Plan) have provided major data
coverage. Unless the data collection efforts are
repeated however, the data quickly become
out of date. On-going monitoring programs
provide the best long-term data that can be
compared over the years. However, a number
of these programs seem to have been ended
in recent years.
Four indicators were used to assess the overall
state of data for all the indicators used in this
report and the background papers: data cover-
age (how well the data cover the Great Lakes
nearshore area); data time frame (how recent
the data are); data applicability (how well data
can be used to address the indicators dis-
cussed in this paper); and data usability (how
well the data can be used across disciplines).
An evaluation of the overall state of data based
on these four categories is presented in Table
1.
Even if standard ecosystem indicators were
selected and data gaps remedied, a daunting
task remains: information management. Infor-
mation management involves the storage,
manipulation, and transfer of information and
data. A number of factors make the manage-
ment of Great Lakes basin ecosystem informa-
tion a challenging task. Something as basic as
generating a list of the available data sets is
very difficult because of a lack of adequate
metadata (information that includes the identifi-
cation of the researcher who collected the
data, the date when data were collected, the
level of accuracy maintained, and the collec-
tion method which). Another difficult issue is
the availability of data for those who want to
use it. Not only can formatting constraints pose
Table I. Overall State of Data
Desired
Outcome
Data to
measure
all
indicators
Indicator
Data
coverage
Data time
frame
Data
applicability
Data
usability
Rating
Fair
Fair
Fair
Fair
Basis for Rating
Only a few date sets cover the entire Great Lakes shoreline. Most
are lake or site specific. Data collected on behalf of international
studies (e.g. surveillance or Lakewide Management Plan studies)
generally have the best data coverage.
Some long term monitoring programs have excellent up to date
data such as the water level information. Large data sets collected
on a one time basis (e.g. shoreline classification) are becoming out
of date.
Most data sets have some applicability to the indicators described
in this report. If they cannot be used directly, they can be used in
support of measuring the indicator.
Some data are useable for a wide range of applications, while
others are very study specific.
Source: Leger, W. and R. Greenwood. 1997. Information and Information Managment. (SOLEC Background Paper)
12
STATE OF THE GREAT LAKES
1997
-------
problems, but questions related to ownership
rights and revenue generation must also be
answered.
The first step in meeting the challenges posed
by information management involves develop-
ing standard methods for collecting, storing,
and maintaining Great Lakes data. The data
must also be made consistent across a range
of computer systems in use throughout the
region. One way to do this is to establish a
database on the World Wide Web that contains
references for all available Great Lakes data.
As long as adequate metadata are available,
decision makers and scientists from all over
the basin would be able to access the data-
base from their own offices and learn where
information exists about a given nearshore
topic. This type of system would eliminate the
need to have actual data located on a Web
site. Today's electronic technology should
facilitate identification and access of data
sources and assembly of information.
4. Indicators
How do we know whether the ecosystem
we are striving to protect (or restore) is
healthy or in need of help? Indicators can
provide simple brief expressions of the state of
the ecosystem based upon aspects that can be
measured and accepted as characterizing its
condition. Such indicators can cover various
levels of the health of the ecosystem, including
biological health, stressors, sources, and
programs to deal with problems at all levels. In
this report we focus on indicators of various
aspects of nearshore ecosystem health.
The health of the living components of the
ecosystem, including humans, is the ultimate
indicator that reflects the total effect of stresses
on the ecosystem. The effects of these
stresses are often expressed as impairments
and are the most meaningful indicators as far
as most people are concerned. Is the system
healthy and can we swim, fish, eat the fish,
and drink the water? Although effects on the
living system are the ultimate indicators, meas-
ures of the physical, chemical, and biological
stressors and sources that affect the system
are equally important in describing the state of
the Lakes and in providing vital information for
programs that address stressors and sources.
For the nearshore areas of the Great Lakes,
there are no widely accepted or generally
available indicators that can be used to
summarize the state of the ecosystem.
Consequently, the authors of the background
papers and the SOLEC 96 conference
organizers developed these indicators. All are
based to some extent upon data, but the
evaluation and rating assigned primarily
amount to the best professional judgment by
knowledgeable people.
For purposes of simplification, a small number
of indicators for each of the background papers
have been chosen for this report. These simple
indicators are intended to summarize, in
understandable language, the state of the
ecosystem and progress being made in
dealing with the many stressors and their
sources. These indicators are presented in
Tables 1, 4, 5, 6, 7, 8, and 9. The reader
should note that there is some variation in the
style of presenting the indicators. For example,
Information and Information Management uses
a rating of good, fair or poor. Nearshore
Waters, Coastal Wetlands and Impacts of
Changing Land Use use a rating system of
good, mixed or poor in conjunction with a
trend. Land by the Lakes: Nearshore
Terrestrial Ecosystems uses a combination of
letter grades A to F, trends and ratings of
good, mixed or poor. More detail about each
indicator can be found in each of the
background papers.
In general, the ratings have the following
meanings:
Poor—significant negative impact.
Mixed—the impact is less severe.
Good—the impact or stress is removed
and that the state of the ecosystem
STATE OF THE GREAT LAKES — 1997
13
-------
Definition of the Term
"NEARSHORE AREAS"
For the purposes of SOLEC 96 and this report, the nearshore areas of the Great Lakes are defined in terms of
living ecosystems, both on land and in the water.
The land areas are those ecosystems directly affected by the Lakes. The water areas are the relatively warm
shallow areas near the shores. The nearshore zone also includes coastal wetlands that are dependent on lake
levels. In both directions, nearshore areas are generally within 16 kilometers (10 miles) of shore. Exceptions are
in Lake Superior, where warm water seldom extends far from shore, and in Lake Erie, where both the central and
western basins are relatively shallow and warm and thus are considered to be nearshore" in their entirety.
On land, the nearshore zone is that area affected by the Lakes—waves, wind, ice, currents, temperature, and the
rising and falling of lake levels that constantly shape and modify the entire shoreline.
In water, the nearshore zone consists of areas with enough warm water to support a community of warmwater
fish and associated organisms. These areas represent approximately 25 percent of each of Lakes Michigan,
Huron, and Ontario; 90 percent of Lake Erie; and only 5 percent of Lake Superior because of its very deep and
cold nature. In general these are coastal areas of less than 30 meters (98 feet) in depth except in Lake Superior
where they are less than 10 meters (33 feet) in depth. The nearshore waters also include the connecting chan-
nels and virtually all the major embayments of the system.
Beyond the nearshore areas and their lake-associated ecosystems (on land and in water), the SOLEC 96 back-
ground paper Impacts of Changing Land Use" discusses sources of stressors affecting the nearshore areas.
These source areas extend upstream far beyond the nearshore area to include virtually the entire Great Lakes
basin.
component is restored to a presently
acceptable level.
In general, the trends have the following
meanings:
* Deteriorating—the trend is towards
greater impact.
Stable—no change in the impact.
• Improving—the trend is towards less
Impact.
It is the intention of the Parties to the GLVVQA,
in SOLEC 98, to focus on the development of a
set of indicators for the governments to report
on the restoration and preservation of the
Great Lakes basin ecosystem.
5. The Nearshore
The Great Lakes are bordered by 16,000
kilometers (10,000 miles) of shoreline,
every kilometer of which represents a unique
and dynamic intersection between life on land
and life in the water. The Great Lakes
nearshore ecosystem is defined by this
intersection, and the ecological result is an
array of unique habitats for the many species
of plants and animals around the basin.
The Great Lakes basin ecosystem includes the
Lakes and the entire area draining into them.
The nearshore consists of interactive areas
where the Lakes influence land and where land
directly influences the Lakes. The remainder of
14
STATE OF THE GREAT LAKES—1997
-------
the basin is important as a source of stressors
affecting the nearshore.
The nearshore areas, both aquatic and
terrestrial, are the most diverse and productive
parts of the Great Lakes ecosystem and at the
same time support the most intense human
activity. As a result, the areas that contain the
greatest biological resources are subject to the
greatest stress. These are the areas most
used by humans and where the majority of
humans live (33 million residents live near the
Lakes). Consequently, these are the areas with
the most to save and the most to lose. Today,
activities ranging from farming to city building
and even recreation affect the basin's
ecosystem.
Great Lakes nearshore areas suffer from a
disproportionate environmental burden
because of their distinctive and sensitive
environments and proximity to development.
This report focuses on the unique physical
environments found in the nearshore
(especially the nearshore waters, the coastal
wetlands, and the terrestrial nearshore—the
land by the Lakes), the health of communities
whose survival depends on those
environments, the major stressors acting on
the nearshore ecosystem, and the sources of
those stressors.
5.1 The Nearshore Waters
5,1.1 Physically Unique
The nearshore waters occupy a band of
varying width around the perimeter of each
Lake, where the water is relatively warmer and
shallower than the rest of the waters in the
Lakes (Figure 4). For the SOLEC 96
conference and this report, the nearshore
Nearshore Waters of the Great Lakes
N
Legend
i Nearshore waters
25 ^0 ~~" 125km
Figure 4. Nearshore Waters of the Great Lakes
Source: Edsall, T. and M. Charlton. 1997. Nearshore Waters of the Great Lakes, (SOLEC 96 Background Paper)
STATE OF THE GREAT LAKES —1997
15
-------
waters are defined in terms of depth and
temperature. The amount of nearshore water
in each Lake varies with the size and shape of
that Lake's basin (see the nearshore definition
above), If the Lake bed is very steep, the
boundary between nearshore and offshore
waters occurs relatively close to shore (less
than 5 percent of Lake Superior is considered
nearshore). If the Lake bed slopes very
gradually, however, the boundary extends
much farther out from the Lake edge (more
than 90 percent of Lake Erie is considered
nearshore).
The difference between nearshore and
offshore waters is dictated by the temperature
during the warmer, ice-free months of the year.
Waters at different temperatures have different
densities and, as a result, warmer, less dense
waters near a lake surface do not mix with
cooler, denser waters deeper in a lake. When
the exchange between nearshore and offshore
water is limited, both plant and animal
communities are affected. Nutrients that enter
a lake via land runoff or point source
discharges are mostly available in the
nearshore; suspended sediments that are
delivered by river outflows have their primary
effect in the nearshore; and pollution that is
discharged into the nearshore waters is
concentrated there. These effects are
particularly noticeable during the spring season
before warmer water spreads over the surface
of a lake.
The Great Lakes connecting channels (the
large rivers carrying the surface-water outflow
from one Great Lake to the next) and the
Lake Ontario Number Bay
0.08 -
,-s 0.07 -
— '
JE, 0.06 -
3 0.05 -
O
i" 0.04 -
O
.c
- 0.03 -
O
*3 0.02 -
O
g: 0.01 -
0.00 -
c
September 1 991
\
\
\
\
* \
\" —
1 • I
) 1000 2000
— • — TP surface
— * — TP filtered surface
— A — CHLa surface
•
1 '
v * .-' c , '?**- ' ^ .„*.-»'
—A,
3000
•
~
•
5
O
4 fE
0)
O
3 9
O
0
T3
3"
*<
2 —
IE"
1 ^
0
4000
Meters from Shore
Figure 5. Phosphorus and Chlorophyll a Gradients in Lake Ontario
Source: Edsall, T. and M. Charlton. 1997. Nearshore Waters of the Great Lakes. (SOLEC 96 Background Paper)
16
STATE OF THE GREAT LAKES
1997
-------
lowest reaches of all Great Lakes tributaries
are also considered nearshore waters. Water
discharged through tributaries into the
nearshore waters contains materials and
energy from the terrestrial and aquatic inland
components. Thus, the nearshore waters are
physically and biologically linked with other
ecosystem elements in the basin.
Nutrient levels can be significantly higher in the
nearshore since nutrients are introduced to a
lake at the shore both by sewage sources and
by rivers. Sewage treatment plant effluent and
combined storm outflows influence nearshore
water quality near population centers. Though
sewage plants remove much of the
phosphorus from sewage, they do not
eliminate it. Many treatment plants discharge
effluents with phosphorus concentrations in the
range of 1,000 micrograms per liter, which is
100 times the desired concentration in the
open waters of, for example, Lake Ontario.
Thus, nearshore-offshore gradients are to be
expected. An example of this gradient can be
seen in Figure 5.
5.1.2 Health of the Nearshore
Waters
While the past 25 years have seen general
improvements in nearshore aquatic ecosystem
health, ample evidence still exists that
physical, chemical, and biological stressors
continue to have a negative impact on
nearshore populations.
The state of the Great Lakes fish community is
one important indicator of nearshore aquatic
ecosystem health, since virtually all species of
Great Lakes fish use the nearshore waters for
one or more critical life stages or functions.
The health of the fish community as an
indicator has been assessed as part of the
status of native species and their habitat, and
is rated as mixed/improving in Table 4. For
some species, the nearshore area is a
permanent residence; for anadromous fish, the
nearshore is a migratory pathway; and for other
offshore species, the nearshore provides
temporary feeding and nursery grounds.
Shallow waters act as a refuge for young-of-
the-year fish, complete with submergent
vegetation for food and protection, and warmer
temperatures that speed growth. Only
deepwater ciscoes (members of the whitefish
family) and sculpins are rarely found in the
nearshore waters.
During the summer, the nearshore waters are
occupied by aquatic plant and animal
communities that are adapted to the summer
thermal conditions there. Each species of fish
has a narrow and relatively unique range of
summer temperatures at which the fish grow
best. Fish actively seek their preferred range
during the summer, resulting in distribution of
species based upon thermal conditions. An
outcome of this is that not all areas of
nearshore habitat are available to all species.
Historically, the loss of biodiversity and the
establishment of non-indigenous species have
bean little short of catastrophic to the Great
Lakes fish population. Most species were
severely reduced in numbers, with many
genetic strains and some entire species lost
entirely. Although many fish communities
remain unstable, management efforts are
working to restore stability. Fish-stocking
activities take place throughout the basin and
habitat restoration projects are becoming more
common. Signs of success include populations
of lake trout reproducing again in Lakes
Superior and Michigan, and beginning to
reproduce in Lake Ontario; walleye and yellow
perch once again being abundant in Lake
Huron; and lake whitefish showing good
recovery throughout the Lakes. The recovery
of native fish stocks alone, however, has been
insufficient to support the Great Lakes
fisheries. Non-native species such as Pacific
salmon, rainbow trout, and brown trout have
been stocked successfully, and have
contributed to the stability in Great Lakes
fisheries, resulting in an industry worth more
than U.S. $4 billion annually. Over 80 percent
STATE OF THE GREAT LAKES —1997
17
-------
of this is retained in the Great Lakes basin,
much of it having a significant impact on small
lakeshore communities.
In spite of a heightened awareness of the
importance of maintaining high-quality fish
habitat, there are still many cases of habitat
destruction that threaten the survival of Great
Lakes fish populations—for example, shoreline
modification. Natural shorelines are often
armored to eliminate erosion that is caused by
wind and wave activity. Artificial hardening of
the shoreline can redirect wave energy,
changing sand distribution and causing erosion
downshore. Irregularities in the shoreline are
often straightened, changing the longshore
currents, which in turn decrease local variation
in the lake bed. The ultimate result is a
significant reduction in the amount of fish
habitat.
Habitat is also disrupted by the passage of
large commercial vessels through harbors and
connecting channels. These ships cause rapid
fluctuations of water levels and disrupt normal
flow conditions to such a degree that
submerged aquatic plants are fragmented or
uprooted, and the substrates that provide
attachment for these plants are eroded.
Recreational watercraft can also cause similar
problems with their wake and propeller action.
The result is a substantial increase in the living
plants, decaying plants, and benthic (bottom-
dwelling) invertebrates that are destroyed,
leaving valuable fish habitat degraded. A more
detailed explanation can be found in section
8.7. The status of native species and their
habitats is an indicator which has been rated
as mixed/improving in Table 4.
A common forage fish, the spottail shiner, was
used to monitor chemical contaminants in the
nearshore in a 1993/94 study that sampled a
total of 44 sites on Lakes Huron, St. Clair, Erie,
and Ontario, and on the St. Clair, St.
Lawrence, and Detroit Rivers. Higher
contaminant values in the sampled fish were
generally more frequent in the lower Great
Lakes, with the maximum observed values
noted at the Grasse River and Reynolds
Aluminum sites in the St. Lawrence River and
at the Welland Canal (Figure 6). In general,
contaminant trends have been declining since
the mid-1970s. The levels of contaminants in
spottail shiners was assessed as part of the
indicator for levels of persistent toxic
substances in water, sediment, fish, and
wildlife and was rated as mixed/improving in
Table 4.
There is strong circumstantial evidence from
laboratory exposure studies and field
observations, linking the occurrence of
cancerous tumors in fish with exposure to
localized areas of sediments that are
contaminated with chemical carcinogens, such
as polynuclear aromatic hydrocarbons (PAHs).
Tumors have been found in populations of
bottom-dwelling species, including brown
bullhead, white sucker, common carp, bowfin,
and freshwater drum. Epidermal papillomas
(tumors on the skin that appear as raised
lumps or bumps, which may become
cancerous) have been found on brown
bullhead in a number of locations, with highest
incidences at locations with elevated levels of
PAHs in the sediment. Table 2 shows tumor
frequencies in brown bullhead populations at
selected sites (Figure 7). External tumor
frequency exceeded 40 percent in Hamilton
Harbour and 50 percent in Presque Isle Bay,
and these tumors were prevalent in about 25
percent of the populations in the Buffalo and
Black Rivers. Buffalo River and Presque Isle
Bay also had about 20 percent incidence of
liver tumors, and the Cuyahoga and Detroit
Rivers had about 8 to 10 percent prevalence.
All these sites have elevated levels of PAH in
at least some portion of their sediment and
have been designated Areas of Concern.
Bullhead from two relatively uncontaminated
sites had a liver turnor prevalence greater than
5 percent, though these populations had a
greater percentage of older fish (age 5 and up)
than the industrial sites. Tumor frequency
tends to increase with age in brown bullhead
populations.
18
STATE OF THE GREAT LAKES—1997
-------
Forage Fish Contaminant Index S PCB (ng
0 2 4 0 200
LAKE HURON
Collingwood
Sydenham River
Maitland River
Perch Creek
ST.CLAIR RIVER
Lambton Gen. Station
LAKE ST.CLAIR
South Channel
Mitchell Bay
Thames River
Peche Island
DETROIT RIVER
Amherstburg
LAKE ERIE
Big Creek ._
Leamington
Grand River
Thunder Bay Beach
NIAGARA RIVER
S DDT (ng g-1)
100 200
Fort Erie ______
Frenchman* Creek
Cayuga Creek N.Y.
Search & Rescue N.Y.
Welland River East
Welland River West
Queenston
Lewiston N.Y.
Niagara-on-the-Lake
LAKE ONTARIO
Welland Canal
Twelve Mile Creek
Twenty Mile Creek
Burlington Beach
Bronte Creek —
Credit River
Etobicoke Creek
Number River
Toronto Harbour
Rouge River
Oshawa Creek
Cobourg Creek
ST.LAWRENCE RIVER
MacDonnell Island
Cornwall Marina
Cornwall Island North
Pilon Island
Thompson Island
Grass River
Reynolds Aluminum
G.M. Plant
Regis Island South
Figure 6. Contaminant Concentrations in Spottail Shiners
Source: Edsall, T. and M. Charlton. 1997. Nearshore Waters of the Great Lakes. (SOLEC 96 Background Paper)
STATE OF THE GREAT LAKES —1997
19
-------
Brown Bullhead Tumor Survey Sites
lake Superior
Munusoong Bay
•j
Menominee River
Fox River
•
«
I
Plum Creek
Detroit River
"# Hamilton
Harbour
Long Point Bay
Y -">-
f*J , '&' *{
dW
Buffa|o R|
" Presciue |sle
_ * Ashtabula River
\- - Cuyahoga River
Black River
50 0
250km
Old Woman Creek •'
Figure 1'. Brown Bullhead Tumor Survey Sites
Source: Edsall, T. and M, Charlton. 1997. Nearshore Waters of the Great Lakes. (SOLEC 96 Background Paper)
While dredging is one method of solving
contaminated sediment problems, it may
create more problems for the aquatic
community, at least in the short term, as
illustrated in the following example. In 1982 a
population of bullhead located near an
operational coking facility at a steel plant on
Ohio's Black River had a liver cancer
prevalence of 38.5 percent. The coking facility
was closed in 1983, and by 1987, PAH
concentrations in surficial river sediment had
declined to 0.4 percent of the concentration
that had been measured in 1980. By 1987, the
cancer frequency in the bullhead population
had also declined, to about one-fourth of that
measured in 1982. Areas of sediment most
contaminated with PAH were subsequently
dredged from the river in 1990. Two years later
the cancer incidence in bullhead exceeded that
in 1982. This case illustrates that additional
sedimentation can be effective in reducing the
incidence of cancer in bullheads in some
systems, whereas dredging with traditional
methods can result in at least a temporary
increase in cancer incidence and degradation
of the health of native species because toxic
contaminants are released from the sediments.
This points to the importance of thorough
analysis of positive and negative, long-term
and short-term impacts of dredging in planning
for remediation. The status of contaminated
sediments has been assessed as one part of
the indicator for levels of persistent toxic
substances in water, sediment, fish, and
wildlife and has been rated as mixed/improving
in Table 4.
Biological stressors also play an important role
in dictating the health of the nearshore aquatic
ecosystem. While managers spend millions of
20
STATE OF THE GREAT LAKES
1997
-------
Table 2. Prevalence of Tumors in Brown Bullhead Populations in Waters of the Great Lakes Basin
Location
Ashtabula River, OH
Black River, OH
Buffalo River, NY
Plum Creek, Ml
Cuyahoga River, OH
Menominee R., Wl and Ml
Fox River, Wl
Detroit River, Ml
Hamilton Harbour, ON*
Presque Isle Bay, PA
Long Point Bay, ON"
Munuscong Bay, Ml**
Old Woman Ck., OH"
Collection
Date
1991
1982
1987
1992
1993
1988
1985
1984
1984
1984
1985-87
1994
1992
1985
1984
1984-85
1992-93
External Tumors
Neoplasms
(%)
16.0
25.0
23.0
7.0
8.9
2.1
7.7
10.0
41.0
56.0
15.0
3.2
2.5
Malignancies
(%)
NA
NA
NA
NA
5.5
NA
1.9
NA
NA
33.0
NA
NA
NA
Liver Tumors
Neoplasms
(%)
6.2
60.0
32.5
58.0
19.0
9.4
8.8
4.5
22.0
5.9
5.6
Malignancies
(%)
3.1
38.5
10.0
48.0
5.0
NA
NA
0
6.9
2.9
3.2
Source for Table 2 (except Hamilton Harbour data): Edsall, T. and M. Charlton. 1997. Nearshore Waters of the Great
Lakes. (SOLEC 96 Background Paper)
* Source: Victor Cairns (1997) Personal communication. Department of Fisheries and Oceans Canada, Canada Centre
for inland Waters, Burlington, Ontario.
" Reference site in relatively pristine area.
NA means that brown bullheads from that site have not been analyzed for malignancies.
dollars on controlling the impact of non-native
(or exotic) species, such as the sea lamprey,
on fish populations, other exotic species
continue to affect the nearshore system. For
example, Bythotrephes is an exotic
zooplankton species, which was introduced
into the Great Lakes in the 1980s. Zooplankton
are the primary (or first level) consumers in the
aquatic food chain; they filter and eat algae,
and their growth provides energy and nutrients
in a form usable to fish. Bythotrephes have
disrupted the native food chain because they
eat other zooplankton (placing additional stress
on the native zooplankton population) and
compete directly against young-of-the-year
fish.
The zebra mussel is a more commonly known
invader, which has also had a dramatic
influence over the state of the nearshore
aquatic ecosystem. One significant negative
impact of the zebra mussel has been the
STATE OF THE GREAT LAKES —1997
21
-------
Lake Erie
1600 •
800 •
E 0 '
"*: 1600 "
is
^ 800-
3^
1 -
0) 1600 •
Q
c
3 800 •
c
JS 0-
o 800"
21
^ 400 •
0 •
A f\ o c- ,A , Union
A / \ 0\ First Appearance of
o] °N°° \ A / I A ^ pZebraMUSSe'S
O \ / n ^ ^
Nutrient control^1 o°ooo 0ooooo°o0ooOoooooo0ooo
0 0
A 0 A Blenheim
° o Ooooooooooooooooo°oooo
.. . /i /VA , I
°O ° OO OOc
Elgin
i
OOOO°°OOOOOOOOO
o 1
f\ Dunnville I
1987 1988 1989
1990
V
1
E
V
MB
Figure 8. Phytoplankton Density in Lake Erie, Showing the Effect of Zebra Mussels
Source: Edsall, T. and M. Charlton. 1997. Nearshore Waters of the Great Lakes. (SOLEC 96 Background Paper)
substantial reduction in species and numbers
of large freshwater clams. The Lake St. Clair-
western Lake Erie corridor once had the
richest and most diverse assemblages of large
freshwater clams in North America. Within six
years of the discovery of the zebra mussel in
this region, freshwater clam populations in the
region had declined to almost zero.
Biodiversity has declined sharply as the
functional community has shifted from a stable,
slow-growing, multi-species clam community in
balance within the ecosystem to a single-
species population of zebra mussels with a
relatively high turnover rate of energy that
strongly affects ecosystem dynamics.
Zebra mussels have had other impacts on the
nearshore aquatic ecosystem—one of which is
shown in the following example. Zebra mussels
feed by filtering particles from the water. This
filtering process affects the nearshore
ecosystem food chain because phytoplankton
and smaller zooplankton, along with other
suspended materials including pollutants, are
removed from the water by the zebra mussels
and biodeposited at the bottom of the lake.
This process greatly reduces the plankton
community (Figure 8) and, therefore, reduces
the amount of food available to planktivorous
(plankton-eating) fish that feed above the
bottom. In turn, the process greatly increases
the food supply for benthic communities and
bottom-feeding fish. The result has been an
increase in benthic species, and those
considered to be pollution-sensitive have since
become dominant. The impact of exotic
species on the Great Lakes aquatic nearshore
22
STATE OF THE GREAT LAKES
1997
-------
Table 3. The State of Nearshore Bird Populations
Type
Colonial
waterbirds
\Afeterfowl
Piscivorous
raptors
Species
Ring-billed
Herring gulls
Double-crested cormorants
Caspian tem
Great blue heron
Great egret
Great black-backed gull
Common tem
Black-crowned night-heron
Black tem
Footer's tern
Little gull
Dabblers
Geese
Bay ducks
Mergansers
Goldeneye
Seaducks
Osprey
Bald eagle
Frequency
Common
Common
Common
Common
Common
Uncommon
Uncommon
Common
Common
Uncommon
Uncommon
Uncommon
Common
Common
Common
Common
Common
Common
Varies with location
Varies with location
Population
Stable or Increasing
Stable/Variable
Stable/Variable
Decreasing
Stable
Stable
Stable/Variable
Stable
Stable
Increasing
Stable or Increasing
Stable
Source: Edsall, T, and M, Charlton. 1997. Nearshore Waters of the Great Lakes. (SOLEC 96 Background Paper)
has been evaluated as poor/deteriorating in
Table 4.
A different factor influencing benthic
communities is the improvement in oxygen
levels in bottom waters of harbors and some
open lake areas such as the central basin of
Lake Erie where populations of the burrowing
mayfly are showing dramatic recovery,
providing evidence of improved benthic
conditions. These changes result primarily
from pollution control although that may be
complemented by the activity of zebra
mussels.
Another indicator of the state of the nearshore
aquatic ecosystem is the health of the wildlife
population. Table 3 illustrates the state of bird
populations dependent on nearshore waters.
While the populations of most colonial
STATE OF THE GREAT LAKES —1997
23
-------
waterbird, waterfowl, and fish-eating raptor
species are stable or increasing, notable
exceptions are the black tern, Forster's tern,
and the little gull. Interestingly, zebra mussels
may have provided a winter boost for the duck
species that feed on molluscs. However, the
long-term impacts on waterfowl populations
are not known.
5.1,3 Human Health
Sufficient evidence exists that consumption of
contaminated sport fish and wildlife can
significantly increase human exposure to Great
Lakes pollutants because of bioaccumulation
and biomagnification in the food chain. A
series of studies in the 1980s linked PCB
exposure in humans to consumption of
contaminated fish. More recently, it has been
demonstrated that consumers of contaminated
Great Lakes fish can have body burdens of
PCBs, mercury, and lead that are twofold to
fourfold higher than those in the general
population.
Just as fish consumption advisories indicate
the level of toxic contaminants entering the
water, beach closures and drinking water
advisories act as indirect indicators of
nearshore water quality. In Canada and the
U.S., most public beaches are monitored to
help ensure that bathers are protected from
contact with polluted water. However, water
sampling and microbiological testing
procedures have not been standardized
throughout the Great Lakes basin. Also, the
kinds and levels of microbes and pollutants
found on any given beach can vary with the
type of contamination (for example, storm-
sewer outfalls, agricultural chemicals and
wastes, or industrial pollution), with water
currents and water temperature, with nutrient
levels, and with the number of beach users,
etc. These variables make it difficult to see
patterns or trends in the microbial quality of
nearshore waters at public beaches across the
Great Lakes, or even at any one given beach.
The nearshore waters may contain disease-
causing organisms (for example, viruses,
bacteria, and protozoa) that can cause
gastrointestinal illness and ear infections as a
result of swimming. Overall, beach closings are
generally due to elevated levels of bacteria, but
take place less frequently in northern regions,
where human population is low and there has
been little industrial development. Conversely,
more closings occur in southern regions,
where the shoreline is more intensely
developed, population densities are high,
extensive industrial and agricultural
development has taken place and water
temperatures along the nearshore are warmer.
During this century, waterborne infectious
illnesses became rare in the Great Lakes
basin, owing to effective treatment of drinking
water and sewage by chlorination, and to
immunization programs. Prior to the treatment
of drinking water, waterborne illnesses such as
typhoid fever and cholera could affect a
significant proportion of an urban population.
For example, in 1854, Chicago experienced a
cholera epidemic in which 5 percent of the
population perished, and in 1891, the death
rate due to typhoid fever reached a high of 124
per 100,000 people. However, even modern
water treatment plants have weaknesses. In
1993, about 400,000 inhabitants of Milwaukee
became infected (about 4,000 were
hospitalized) by a protozoan parasite
(Cryptosporidium). A smaller outbreak of
cryptosporidiosis occurred in Collingwood,
Ontario, in 1996.
Some sewage treatment plant discharges are
not disinfected before release, especially
during storm flows, and thus contribute to the
pathogenic load of nearshore waters. In
addition, some sewage plant effluents,
especially those carrying industrial wastes, are
toxic to algae and probably also to other
aquatic organisms. Other effluents such as
agricultural runoff also contain pathogens and
toxic chemicals. The chemical disinfectants
used to kill pathogens in sewage and in
24
STATE OF THE GREAT LAKES—1997
-------
Table 4. Indicator Ratings for the Nearshore Aquatic Ecosystem and Stressors
Desired Outcome
Healthy fish and
wildlife
Virtual elimination of
persistent toxic
substances
Reduced nutrient
loading, eliminating
eutrophication
Healthy human
populations
Indicators
Effect of exotic species
Status of native species and their habitats
Levels of persistent toxic substances in water
and sediment
Concentrations of persistent toxic substances in
fish and wildlife
Dissolved oxygen concentrations of bottom
waters
Water clarity/algal blooms
Fish consumption advisories
Beach closings, measured in median number of
consecutive days closed for a given year
Drinking water quality
Acute human illness associated with locally high
levels of contaminants
Chronic human illness
Overall state of the Great Lakes aquatic nearshore ecosystem
Condition
Poor
Mixed
Mixed
Mixed
Good
Mixed
Mixed
Inadequate
data
Good
Inadequate
data
Inadequate
data
Mixed
Trend
Deteriorating
Improving
Improving
Improving
Improving
Improving
Improving
Unknown
Stable
Unknown
Unknown
Improving
Source: SOLEC 96 Steering Committee
drinking water can also create toxic by-
products.
Sewage water and drinking water are usually
disinfected through the use of chlorine and
occasionally ozone. Historically, municipalities
began treating drinking water to prevent
waterborne disease, by adding chlorine as a
disinfectant. This proved to be a simple
solution to a very serious public health
problem. Chlorine is still used because it can
kill pathogens throughout the water distribution
system. Human health indicators have been
evaluated in Table 4 and range from good/
stable to mixed/improving. However, for many
of the indicators there are inadequate data
available to determine a rating.
5.1.4 Overall Rating
Table 4 summarizes the state of nearshore
aquatic ecosystem health. The indicators that
have not been discussed in this report are
supported in the background paper "Nearshore
Waters of the Great Lakes".
STATE OF THE GREAT LAKES —1997
25
-------
(a) OPEN SHORELINE
(b) UNRESTRICTED BAY
.>^~
•EJ* -»•
^.*-^Fd
— *" rr
J\
~ - « \
sand
sand dune
(c) SHALLOW SLOPING BEACH
_-=**1^" =^ £<£. ^f
* .L*7 V fiT^lllF1 "zl-.
«•" *r-r~ -*" WTT- •*".
-T .1.- * »— -?^T —
~ « -~ .-*— ^»- *
(d) RIVER DELTA
restrictive
backslope
(e) RESTRICTED RIVERINE (f) LAKE - CONNECTED INLAND
\'J yjJJ 11 ij^LO, J..1.AJ- IT
barrier beach
(g) BARRIER BEACH
^^^^^^i
xdike
(h) DIKED
Figure 9. Different Types of Great Lakes Coastal Wetlands
Source: Maynard, L. and D. Wilcox, 1997. Coastal Wetlands. (SOLEC 96 Background Paper)
26
STATE OF THE GREAT LAKES—1997
-------
High water levels: landward shift of vegetation communities
Low water levels: lakeward shift of vegetation communities
Uplands ;Wet Meadow strand
woody
vegetation
Emergent Marsh
emergent macrophytes
Aquatic
floating-leaved and
submergent macrophytes
max. high water level
present water level
Figure 10. Shifting Plant Communities in Coastal Wetlands
Source: Maynard, L and D. Wilcox. 1997. Coastal Wetlands. (SOLEC 96 Background Paper)
5.2 The Coastal Wetlands
5.2.1 Physically Unique
There are four basic types of wetlands;
marshes, swamps, bogs, and fens. Marshes
and swamps are the most common types of
wetlands found in coastal areas because their
vegetation can tolerate the large short- and
long-term fluctuations in water levels of the
Great Lakes. Although bogs and fens are more
rare, they too are represented in sheltered
areas adjacent to the Lakes.
Great Lakes coastal wetlands are shaped by
dynamic lake processes, including waves,
currents, and fluctuations in water levels, both
long-term and seasonal. They are vibrant and
unique areas of unrivaled importance to the life
of the Lakes. They occur along the shorelines
of the Lakes in areas where the erosive forces
of ice and wave action are low, thus allowing
the growth of wetland plants. Figure 9
illustrates the variety of wetland types.
The ecological characteristics of Great Lakes
coastal wetlands are controlled by natural
stress. Seasonal and long-term water-level
fluctuations represent the most Important
source of stress, limiting the invasion of woody
vegetation by causing lakeward or landward
shifting of plant communities (Figure 10).
Individual wetland species and vegetative
communities prefer, and have adapted to,
STATE OF THE GREAT LAKES—1997
27
-------
certain water depth ranges, allowing wetlands
to be more extensive and more productive than
they would be if water levels were stable.
Differences between long-term recorded all-
time high and low water levels range from 1.1
to 2 meters (3.6 to 6.5 feet) depending on the
Lake.
5.2.2 Health of Coastal Wetlands
An assessment of the state of Great Lakes
coastal wetlands must begin with the
recognition that many of the original coastal
wetlands no longer exist. Humans have
drained, filled, and dredged coastal wetland
areas for decades. The majority of these
activities took place on the Lower Lakes, for
agricultural, urban, and industrial land uses.
For example, in western Lake Ontario from the
Niagara River to Oshawa, 83 percent of the
original 3,900 hectares (9,637 acres) of
marshland were mostly lost to urbanization.
Even larger losses occurred on Lake Erie over
the last century and a half, especially in the
western basin, Prior to 1850, there were
122,000 hectares (301,465 acres) of coastal
marsh and swamp between Vermillion, Ohio,
and the Detroit River, Michigan (part of the
Black Swamp, a vast wetland complex). These
wetlands were largely cleared, drained, filled,
and diked to provide agricultural land in the late
1800s. Losses continued so that by 1987 only
5,300 hectares (13,090 acres) of Ohio's
coastal marshes remained.
While the area of wetlands lost each year is
now far less than in previous years, this is
largely because so little remains. Current
losses are a serious problem, as is continuing
loss of quality even in protected areas. Little
data are available on the rate of loss in quality,
but where ecological processes such as
natural water-level variations are disturbed or
when wetlands are invaded by exotic species,
they lose their ability to support sensitive
species as well as their complexity and
resiliency.
More recently, an appreciation has been gained
for the vital role that coastal wetlands play in
the maintenance of Great Lakes ecosystem
health. Coastal wetlands protect nearshore
terrestrial ecosystems from erosion by storing
flood waters and dissipating wave energy; they
reduce turbidity and improve water clarity in
adjacent aquatic systems through sediment
control; and they use a combination of physical,
biological, and biogeochemical processes to
improve water quality. Coastal wetlands are
also home to a variety of plant and animal
species. Over 90 percent of the approximately
200 fish species in the Great Lakes directly
depend on coastal wetlands for some part of
their life cycle. In addition, a number of species
of birds, amphibians, reptiles, and mammals
also depend on wetland habitat. Wetlands in
general are known to provide habitat for many
of the plant and animal species listed as
threatened or endangered. About one-quarter of
the fish species, two-thirds of the birds, and
three-quarters of the amphibians listed as
federally threatened or endangered in the U.S.
are associated with wetlands.
While a comprehensive review of the state of
remaining wetlands requires further research, it
is possible to indirectly assess the health of the
Great Lakes coastal wetlands by reviewing the
stressors acting on them.
The degree of water-level fluctuation in the
Great Lakes is an indirect indicator of coastal
ecosystem health. Coastal wetlands depend on
28
STATE OF THE GREAT LAKES—1997
-------
seasonal and long-term water-level
fluctuations. When water levels are regulated,
the natural range, frequency, timing, and
duration of water-level changes are affected.
As a result, the extent and diversity of wetland
plant communities are reduced, and habitat for
wetland fauna is altered. One consequence of
this subtle yet pervasive environmental
alteration is that coastal wetlands become
more susceptible to invasion by exotic species,
such as purple loosestrife, or aggressive native
plants, such as reed canary grass1. These two
species have established themselves in
coastal wetland ecosystems, forming dense
clumps (often in large, single species stands)
that can choke out more beneficial native
plants and therefore reduce habitat diversity.
Purple loosestrife is particularly destructive
because it has little or no value as food or
cover for wildlife.
A second indirect indicator of coastal wetland
health is the type of land-use activity taking
place in the watershed surrounding coastal
wetlands. Agricultural, residential, and
industrial developments affect coastal
ecosystems in a number of ways. In addition to
having a direct physical impact, they increase
the volume of sediment entering coastal
wetlands and as a result bury fish-spawning
areas. The increased sediment also decreases
water clarity and light penetration into the
water, thereby limiting the growth of the
aquatic plants that form the base of the food
chain. Finally, the high turbidity that results
also restrict feeding by desirable sight-feeding
fishes and favor introduced species like
common carp, which can feed by taste and
smell in highly turbid waters. Other impacts
associated with these types of land uses
include nutrient enrichment and increases in
toxic chemical concentrations.
The extent to which wetlands are diked is a
third indirect indicator of Great Lakes coastal
wetland health. Diked wetlands are believed to
solve management problems under
circumstances where protection from water-
level change and wave action is required or to
help manage waterfowl habitat. However,
diking also creates problems for wetlands.
Isolation from the lake waters and the
surrounding landscape results in the
elimination or reduction of many of the
functional values of wetlands, including flood
conveyance, flood storage, sediment control,
and improvement of water quality. Habitat for
waterfowl and certain other animals may be
improved by diking, but shorebirds and many
less common plants and animals lose the
habitat provided by a continually changing
boundary between land and water. In addition,
fish and invertebrates not capable of overland
travel have no access to diked marshes and
lose valuable habitat. Fish larvae pumped into
diked wetlands during filling operations cannot
leave and are thus lost to the lake population.
5.2.3 Overall Rating
The overall state of coastal wetlands in the
Great Lakes ecosystem is only partially known,
and that is why an overall rating could not be
given. No inventory or evaluation system is in
place for the majority of coastal wetlands. The
general locations of coastal wetlands are
known from remote sensing and aerial
photography, but there is no commonly
accepted system of classification nor is there
systematic information on their quality, rate of
loss, or rate of degradation. Much is known
about the stressors that degrade wetlands and
the conditions of some areas have been
relatively well studied, but it is not possible at
this time to provide a comprehensive review of
the state of Great Lakes coastal wetlands.
Table 5 summarizes the state of coastal
wetland ecosystem health. A more detailed
review can be found in the background paper
"Coastal Wetlands of the Great Lakes."
1The origin of reed canary grass is uncertain—it may be indigenous to the Great Lakes region or other parts of North
America—but it became prominent in some Great Lakes coastal wetlands as a result of human actions.
STATE OF THE GREAT LAKES —1997
29
-------
Table 5. The State of Coastal Wetlands Ecosystems and Stressors
Desired Outcome
Preserve or restore
wetland area
Preserve or restore
wetland area
Preserve or restore
health of the habitat
Preserve or restore
healthy fish & wildlife
populations
Indicators
Land-use changes, encroachment, development
Land use adjacent to wetland
Wetland size, abundance: Upper Lakes
Lower Lakes
Shoreline modification
V\fater-level fluctuation: Lake Ontario
Lake Superior
Unregulated lakes
Protection from erosive forces
Levels of nutrients and persistent toxic chemicals
Status of plant communities
Status of individual plant species
Effect of exotic species
Concentration of persistent toxic substances in
biota
Overall state of the Great Lakes coastal wetlands ecosystems
Condition
Poor
Poor
Mixed
Poor
Poor to mixed
Poor
Poor to mixed
Good
Inadequate
data
Mixed
Mixed
Mixed
Poor
Mixed
Inadequate
data
Trend
Deteriorating
Deteriorating
Deteriorating
Deteriorating
Deteriorating
Stable
Stable
Stable
Unknown
Improving
Deteriorating
Deteriorating
Deteriorating
Improving
Unknown
Source: SOLEC 96 Steering Committee
5.3 The Land by the Lakes
5.3.1 A Unique and Diverse
Landscape
The land by the Lakes (nearshore terrestrial
ecosystems) is defined by the Lakes
themselves. It is the product of ancient glacial
sculpting, continuous etching by waves and
wind, longshore currents, and the steady
deposit of sediment by more than 500
tributaries that constantly modify the 16,000
kilometers (10,000 miles) of shoreline. It may
be as narrow as a beach weathered by wind or
as wide as a forest or dune field that extends
several kilometers inland. It includes unusual
land features such as the towering rock cliffs of
Lake Superior's north shore, the dune and
swale topography of southern Lake Michigan,
the rich-soiled prairie/savanna landscape of
Lake Erie, and the thin-soiled alvars of
northern Lake Huron and eastern Lake
Ontario.
This ever-changing shoreline acts as a buffer
zone between the aquatic ecosystem and
inland terrestrial ecosystems, and interacts
with coastal wetland systems. Sand dunes,
bars, and spits, for example, shelter coastal
marsh and lagoon habitats. Sand beaches are
30
STATE OF THE GREAT LAKES—1997
-------
the staging ground for transferring sand inland
to create dunes. Nutrients, algae, and coarse,
woody debris that collect on nearshore
beaches provide food for birds, fish,
amphibians, mammals, and microscopic
organisms. Nearshore ecosystems provide
important habitat for aquatic invertebrates with
short adult life cycles, and are spawning areas
for amphibians. They are critical habitats for
migratory birds.
The unique shoreline ecosystems support a
diversity of plant and animal species.
Nearshore terrestrial ecosystems are living,
resting, or feeding places for rare or globally
imperiled species such as the piping plover
and the Karner blue butterfly. Several species,
including the Michigan monkey flower and the
Kirtland's warbler, are found only in the Great
Lakes region. The character of the Great
Lakes results from a combination of unique
physical attributes and rich biological
communities.
5.3.2 The Health of the Land by the
Lakes
The health of the land by the Lakes, nearshore
terrestrial ecosystems, is degrading throughout
the Great Lakes. This conclusion was reached
by viewing the nearshore terrestrial
environment from three perspectives: the
ecoregions within the Great Lakes basin, the
special ecological communities along the
lakeshore, and the status of individual Lakes. A
letter grade from "/A" through "P indicates the
quality of the shorelines of 17 ecoregions and
12 special ecological communities, whereas a
Canadian and U.S.
Ecoregions
Canadian \
1 Thunder Bay - Quetico ; 13
2 Lake Nipigon \
3 Abitibi Plains K
4 Lake Timiskaming Lowland \
5 Algonquin - Lake Nipissing
6 Frontenac Axis
7 Manitoulin - Lake Simcoe
8 Lake Erie Lowland
25 0
125km
9 Erie and Ontario Lake Plain
10 Southern Lower Michigan
11 Northern Lacustrine-Influenced
Lower Michigan
12 Northern Lacustrine-Influenced
Upper Michigan & Wisconsin
13 Southeastern Wisconsin Savanna
14 Northern Continental Michigan,
Wisconsin, & Minnesota
15 Northern Minnesota
16 South Central Great Lakes
17 Southwestern Great Lakes Morainal
Figure I I. Great Lakes Coastal Ecoregions
Source: Reid, R, and K. Holland. 1997. The Land by the Lakes: Nearshore Terrestrial Ecosystems. (SOLEC 96
Background Paper)
STATE OF THE GREAT LAKES—1997
31
-------
scale from "good" to "poor" characterizes four
elements regarding the status of individual
Lakes,
5.3.2.1 Ecoregions
Ecoregions are large landscape areas defined
by climate, physical characteristics, and the
plants and animals living there. There are 17
ecoregions in the Great Lakes basin (Figure
11), each with a nearshore terrestrial
component. The extent to which special
ecological communities are represented and
protected within each ecoregion, as well as the
rate of land-use change affecting these
communities determine the ecoregion ratings.
Specifically, an assessment of the quality of
ecoregional shorelines was based on the
following categories:
« characteristic shoreline types
* significant natural communities
• existing representation in parks/protected
areas
• priority unprotected features
» urban area within shoreline watersheds
* agriculture within shoreline watersheds
• residential/cottage/marina shoreline use
* lake edge armored against erosion
• rate of land-use change
* planning/restoration activities under way
« trend in shoreline health
Because of the varying nature of the
ecoregions and their relationship with the
Great Lakes, this approach to assessing the
quality of shorelines works better in some
regions than others. In the ecoregions along
the north shore of Lake Superior, for example,
land uses and stresses are fairly consistent
across the coastal areas of each ecoregion.
But in some of the more southerly ecoregions,
particularly those that front on more than one
Lakes, this degree of generalization may mask
important internal differences.
There is some concern that the ecoregional
ratings are overly generalized. Future
refinements to this approach, perhaps using a
more detailed ecodistrict scale and
incorporating quantitative data wherever
possible, would be valuable.
Only a few of the ecoregions have protection
for areas that represent the full range of
nearshore biodiversity; over half have seriously
inadequate representation, with a trend of
moderate to severe degradation of shoreline
health (Table 6).
5.3.2.2 Ecological Communities
Special lakeshore ecological communities are
places with unique physical features and
habitats that support biodiversity or unique
plant and animal life. The quality of 12 special
lakeshore ecological communities (Table 7)
was rated on the basis of the following:
• percentage of the community remaining
in a healthy state
major stresses
* sources of stress
• processes/functions impaired
• species/communities endangered/
threatened
* stewardship activities in place
* condition or trend (from no change or
stable to severely degrading)
The first category, percentage remaining in a
healthy state, is an estimate of the extent of
each community remaining intact from its
original, pre-European settlement, state. The
other categories relate to current stresses,
impacts, and activities, that affect the future of
the special communities as they exist now. The
condition or trend category relates to trends
over roughly the past two decades. For many
of the communities, trend information is
incomplete, so the ratings have been assigned
and reviewed by individuals knowledgeable in
the field. A more complete analysis of the
current and former distribution of these special
lakeshore communities, trends affecting their
32
STATE OF THE GREAT LAKES—1997
-------
Table 6. The State of Nearshore Terrestrial Health in Great Lakes Ecoregions
Ecoregion
Northern Continental Michigan, Wisconsin, &
Minnesota
Northern Minnesota
Thunder Bay-Quetico
Lake Nipigon
Abitibi Plains
Lake Timiskaming Lowland
Northern Lacustrine-Influenced Upper
Michigan & Wisconsin
Algonquin-Lake Nipissing
Manitoulin-Lake Simcoe
Frontenac Axis
Lake Erie Lowland
Erie and Ontario Lake Plain
Southern Lower Michigan
Northern Lacustrine-Influenced Lower
Michigan
South Central Great Lakes
Southwestern Great Lakes Morainal
Southeastern Wisconsin Savanna
Lake(s) Bordered
Superior
Superior
Superior
Superior
Superior
Superior
Superior / Huron
Huron
Huron / Ontario
Ontario
Erie / Ontario
Erie / Ontario
Huron / Michigan
Huron / Michigan
Michigan
Michigan
Michigan
Rating
B
B
C
B
A
B
B
B
D
C
D
D
C
B
C
C
D
Trend
Stable
Moderately degrading
Moderately degrading
Stable
Stable
Stable
Moderately degrading
Stable
Moderate-severely
degrading
Moderately degrading
Severely degrading
Severely degrading
Moderately degrading
Stable
Severely degrading
Severely degrading
Severely degrading
Source: Reid, R, and K. Holland. 1997. The Land by the Lakes: Nearshore Terrestrial Ecosystems. (SOLEC 96
Background Paper)
future, and management needs would be very
valuable.
Although most of these community types are
undergoing some conservation activities, five
communities are considered to be moderately
or severely degrading. Shoreline alvars and
lakeplain prairie communities are most at risk.
5,3.2.3 Lake by Lake Assessment
Each Lake is also assessed according to four
indicators: retention of communities/species,
retention of natural shoreline processes (un-
armored shoreline), representation of
biodiversity in lakeshore parks and protected
areas, and gains in habitat protection in
STATE OF THE GREAT LAKES —1997
33
-------
Table 7. The State of Special Great Lakes Ecological Communities in the Nearshore
Terrestrial Ecosystem
Special Ecological Community
Sand beach
Sand dune
Bedrock beach/cobble beach
Unconsolidated shore bluff
Coastal gneissic rocklands
Limestone cliffs/talus slopes
Tallgrass prairies
Sand barrens
Arctic-Alpine disjunct communities
Atlantic coastal plain communities
Shoreline alvars
Islands
Major
Stress
H
A
B
1
T
A
T
A
L
T
E
R
A
T
1
O
N
Major
Source
of Stress
C
H
A
N
G
1
N
G
L
A
N
D
U
S
E
Overall
Rating of
Community
Health
C
D
D
C
C
B
F
D
B
C
F
C
Trend
Moderately degrading
Moderately degrading
Moderately degrading
Moderately degrading
Moderately degrading
Moderately improving
Severely degrading
Moderately degrading
Stable
Moderately degrading
Severely degrading
Moderately degrading
Source: Reid, R, and K. Holland. 1997. The Land by the Lakes: Nearshore Terrestrial Ecosystems. (SOLEC 96
Background Paper)
selected "biodiversity investment" areas (Table
8). With several exceptions, four of the Lakes
are rated in the mixed/deteriorating or the poor
category. Lake Superior receives a good rating
in almost all categories.
Given the findings that existing protection and
restoration programs are inadequate to meet
the continuing stresses to habitat and physical
processes, a conservation strategy for Great
Lakes coastal areas is urgently needed. This
strategy should seek to involve all levels of
governments and other stakeholders, reflect
commitments to biodiversity conservation and
sustainable development, and secure broad
support from Great Lakes citizens. It should
place special emphasis on protecting large
core areas of shoreline habitat within the 20
Biodiversity Investment Areas (Figure 17 in
section 9). The Biodiversity Investment Areas
are clusters of shoreline areas with exceptional
biodiversity values that present key
opportunities to create large protected areas
that will preserve ecological integrity and,
ultimately, help protect the health of the Great
Lakes themselves.
34f
STATE OF THE GREAT LAKES
1997
-------
Table 8. Indicators of Overall Ecosystem Health and Stressors for the Land by the Lakes
Lake
take
Superior
Lake
Michigan
Lake
Huron
Lakes
Erie and
St. Clair
Lake
Ontario
Indicators
Retention of shoreline species/communities
Retention of natural shoreline processes, (un-armored shoreline)
Representation of biodiversity in lakeshpre parks & protected
areas
Gains in biodiversity investment areas
Retention of shoreline species/communities
Retention of natural shoreline processes (un-armored shoreline)
Representation of biodiversity in lakeshore parks & protected
areas
Gains in biodiversity investment areas
Retention of shoreline species/communities
Retention of hatural shoreline processes (un-armored shoreline)
Representation of biodiversity in lakeshore parks & protected
areas
Gains In biodiversity investment areas
Retention of shoreline species/communities
Retention of natural shoreline processes (un-armored shoreline)
Representation of biodiversity in lakeshore parks & protected
areas
Gains in biodiversity investment areas
Retention of shoreline species/communities
Retention of natural shoreline processes (un-armored shoreline)
Representation of biodiversity in lakeshore parks & protected
areas
Gains in biodiversity investment areas
Condition
Good
Good
Good
Mixed
Mixed
Mixed
Mixed
Mixed
Mixed :
Mixed
Mixed
Mixed
Mixed
Poor
Mixed
Poor
Mixed
Poor
Mixed
Mixed
Trend
Stable
v Stable
Improving «
fcupro^og :;
Deteriorating
Deteriorating
Stable
Improving
Deteriofiafing
Stable
Improving
Deteriorating
Deteriorating
Deteriorating
Stable
Stable
Deteriorating
Deteriorating
Stable
Stable
Source: Reid, R. and K. Holland. 1997. The Land by the Lakes: Nearshore Terrestrial Ecosystems, (SOLEC 96
Background Paper)
STATE OF THE GREAT LAKES —1997
35
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6. Stress on the Nearshore
As evidenced by the state of ecosystem
health within the three geographical
components of the Great Lakes nearshore, the
nearshore ecosystem continues to be stressed
by human activity. In particular, industrial,
commercial, residential, agricultural, and
transportation-related activities all have specific
and cumulative impacts on the Great Lakes,
their tributary waters, and nearshore areas.
Table 9 illustrates the state of a number of
land-use indicators. Due to their unique and
sensitive environments, and their proximity to
development Great Lakes nearshore areas
bear the brunt of a disproportionate amount of
environmental burden caused by human
activity. This section examines the nature and
source of this burden by focusing on the
different types of stressors to which nearshore
ecosystems are exposed: physical, chemical,
and biological stressors.
6.1 Physical Stressors Including
Land Use
Physical stress can do two things to
ecosystems: it can directly alter habitat and it
can disrupt the functioning of important
physical processes that support the existence
of the habitat. When a piece of land, shoreline,
or lake bed is cleared or substantially modified
for human use, most of the living and non-
living components of ecosystems are
destroyed. Some species cannot move or are
not well-adapted to the altered or diminished
habitat. These conservative species often
require very specific habitat features, which
sometimes include the presence of associated
species. They tend to be relatively rare and the
first to be lost when change occurs. Some
species, however, have broader limits of
tolerance and can continue to inhabit the area.
Even these species can be relegated to tiny
fragments of their original territory. Such habitat
fragmentation makes it difficult or impossible
for isolated individuals within a species to
interact. As a result, the flow of genetic
information that is necessary to sustain
populations is inhibited.
The disruption of physical processes can also
have a devastating impact on the health of
ecosystems. For example, the presence of
sand-starved areas along the Great Lakes
shoreline is the result of human development
activities that interrupt the natural sediment
nourishment process. Shoreline hardening,
breakwaters, bridges, and other artificial
coastal structures are examples of
developments that prevent or accelerate the
erosion of sand in some places, and prevent
the deposition of sand in others.
Development in all its forms is a leading
stressor of the Great Lakes basin ecosystem
and, in particular, the nearshore area. Large-
scale population settlement and development
have gone hand in hand in the Great Lakes
nearshore ecosystem resulting in decades of
physical stress. Today that development
continues. The most significant development
issue in the Great Lakes basin and
surrounding region is the continuing growth of
major metropolitan areas, coupled with growth
of smaller urban centers and development of
recreational areas. Not only are urban areas
growing in population, but the way they are
growing has changed over time. The central
city anchor for rail transportation, multi-story
factories, and apartment life has given way to
36
STATE OF THE GREAT LAKES—1997
-------
Table 9. Land-Use Indicators
Desired
Outcome
Efficient
Urban
Development
Protection of
human hearth
Protection of
resource health
Indicators
Urban population density
Suburban land conversion
Center-town economy (based on fiscal condition, vacancies, etc.)
Brownfields (number & area)
Recreation opportunities (number & area of parks)
Energy use (per capita)
Waste created (residential & industrial)
Wastewater quality (based on nutrient & toxic loadings)
Industrial water use
Residential water use
Traffic congestion
Transit use
Air pollution levels (based on particulates & ozone levels)
Beach closings (number of unswimmabte days)
Land-fill capacity
Stormwater quality (based on nutrient & toxic loadings)
Sewage quality (based on nutrient & toxic loadings)
Pollution-prevention programs (industrial & municipal programs)
Respiratory illness (based on hospital admissions & death records)
Fish advisories
Outdoor recreation (based on opportunities & participation)
Wetland habitat (number & area)
Agricultural & natural land loss (area lost to rural development)
Wildlife populations
Forest clearing (based on cutting rates), replanting & renewal
Mineral extraction
Fishing pressure
Hunting pressure
Hardening of land surface (based on area of roads & buildings)
Municipal pesticide/fertilizer use
Agricultural pesticide/fertilizer use
Conservation tillage
Groundwater quality (based on area/number of contaminated wells)
Contaminated sites (area and number)
Cottage & second homes (number per coastal area)
Condition of
Stressor
Poor
Poor
Mixed
Poor
Mixed
Poor
Poor
Mixed
Mixed
Poor
Poor
Poor
Poor
Inadequate
data
Mixed
Poor
Mixed
Mixed
Mixed
Mixed
Mixed
Mixed
Poor
Mixed
Mixed
Mixed
Mixed
Good
Poor
Poor
Mixed
Mixed
Mixed
Mixed
Poor
Trend
Stable
Deteriorating
Deteriorating
Stable
Improving
Improving
Improving
Improving
hip roving
Stable
Deteriorating
Deteriorating
knprovfng
Unknown
Stable
Stable
Improving
Improving
Stable
hiproving
knproving
Deteriorating
Deteriorating
Stable
Stable
Stable
Deteriorating
Stable
Deteriorating
Stable
hiproving
knproving
Deteriorating
knproving
Deteriorating
Source: Thorp, S., R. Rivers, and V, Pebbles. 1997. Impacts of Changing Land Use. (SOLEC 96 Background Paper)
STATE OF THE GREAT LAKES —1997
37
-------
truck and auto transport, one-story industrial
buildings, sprawling office parks, and expansive
suburban residential areas.
An example of this expansion can be seen in
northeastern Illinois, where the overall
population of the six-county area increased
only 4.1 percent from 1970 to 1990; however,
land consumption increased by an estimated
46 percent. Natural areas as well as
agricultural areas (together identified as
"greenfields") are prime targets for this
development. For example, in Michigan,
farmland was converted to some other use at
the rate of 4 hectares (10 acres) an hour in the
decade between 1980 and 1990. If significant
levels of farmland conversion continue in the
Great Lakes basin, the agricultural production
base will decline and, along with it, the agri-
food sector of the economy.
One of the factors driving the movement of
industry away from urban areas is the problem
associated with redeveloping sites on which
manufacturing operations once thrived. The
Great Lakes basin contains thousands of
former industrial sites (known as "brownflelds")
that have been abandoned because of cleanup
costs and lingering liability associated with the
development of lands, which, in many cases,
are sources of continuing toxic pollution.
Although there is no comprehensive inventory
of brownfleld sites in the Great Lakes basin,
the amount of land categorized as such is
large—possibly tens of thousands of acres.
Much of this land could potentially be
developed for relatively high-density uses.
While the amount of land being absorbed in
current sprawl development is far larger,
redevelopment of brownflelds could contribute
significantly to efficient and sustainable urban
development.
It is reasonable to assume that development
activities will continue to physically stress
nearshore ecosystems because the
responsibility for land-use decisions that affect
the ecosystem is fragmented among a very
large number of government entities.
Government jurisdictions within the basin
include two federal governments; one province
and eight states, each with a myriad of
agencies; 13 regional and 18 county
municipalities in Ontario, many regional
planning commissions and councils of
government, and 192 counties in the U.S.;
thousands of U.S. local governments and
about 250 Canadian local governments; and
more than 100 First Nations and tribal
authorities. In addition, significant influence is
brought directly to the development approval
process by private sector developers and
consultants, non-profit organizations such as
environmental groups and residents' groups,
the media, and the public. The greatest degree
of decision-making authority regarding land
use rests with local governments.
A different kind of physical stress is created by
thermal-electric power plants, which cause
substantial fish mortality. Most of the power in
the Great Lakes basin is produced by these
plants, which use large volumes of water to
cool and condense steam in the power
generation cycle. About 90 thermal-electric
plants draw their cooling water directly from the
nearshore waters of the Great Lakes and use a
once-through cooling process. The water is
first drawn through screens and then passed
through the plant's heat exchangers, where a
temperature increase of between 4° and 20°
Celsius occurs before the water is discharged
into the Lake. Fish that are small enough to
pass through the entry screens are drawn into
the plant with the cooling water. They are then
killed either by colliding with other screens and
surfaces in the system or by heat shock. Fish
that are too large to pass through the screens
are caught on the screens and killed. Research
in the early eighties indicated that thermal-
electric power plants in Lake Michigan killed
more than 75 billion fish eggs and larvae
annually. A single pumped-storage hydro plant
on the Lake's eastern shore killed more than
400 million fish larvae and more than 100
million juvenile alewife, yellow perch, and
salmon annually. While efforts continue to be
made to mitigate the negative impact of these
38
STATE OF THE GREAT LAKES—1997
-------
plants on Great Lakes fish populations, the
plants remain a stress on the nearshore
ecosystem.
The final physical stress to be mentioned in
this report is an emerging concern not only to
those living in the Great Lakes basin but to
human populations around the world—namely,
climate change and variability. Mathematical
models suggest an average warming of 3° to
8° Celsius for the Great Lakes basin
(depending on the season and the location) by
the latter half of the next century. The greatest
impacts are expected to be indirect changes in
other climate conditions, not just temperature
change. Rainfall patterns, soil moisture,
evapotranspiration, snow-season length,
extreme heat, and the frequency and severity
of weather disasters such as thunderstorms,
hail, and tornadoes are all expected to change
regionally. The most profound direct impact
would be on the hydrological cycle.
Consequences could include a decline in the
overall basin water supply of 2 to 113 percent,
a subsequent decline in outflow to the
freshwater portion of the St. Lawrence River
basin of 20 to 40 percent, a decline in
groundwater recharge rates, an increase in
evaporation rates leading to increases in the
frequency and severity of drought conditions,
and a shift in both terrestrial and aquatic
species as those dependent on cooler climates
move north. Climate change and variability
may have consequences for agriculture,
forestry, and urban infrastructure within the
basin.
In the past, studies have focused on water
quality; however, with climate change and
variability, water quantity in the basin may
become an increasingly important issue. Mean
water levels could be reduced on all the Great
Lakes. This would therefore affect the
regulation of water levels on Lake Ontario.
Lower water levels would also disrupt Great
Lakes coastal wetland ecosystems. Less water
may lead to poorer water quality, since dilution
of point source contaminants would not be as
great; and the relative importance of
contaminants originating from other sources
(rainfall, groundwater, surface flow, or release
from lake sediments) would be modified.
Figure 12 illustrates the potential impact of one
climate change scenario on Lake St. Clair
water levels. The volume of Lake St. Clair
could be reduced by 37 percent and the
surface area could decrease by 15 percent.
These water-level declines may displace the
shoreline by as much as 6 kilometers (4 miles)
from its present location, exposing large areas
of lake bottom. This would adversely affect
wetlands, marinas and recreational boating,
commercial navigation, and public water supply
intakes.
Climate change models predict progressive,
linear changes through time. However,
ecosystem response is most likely to be non-
linear, with an apparent resistance to change
up to a certain threshold, beyond which a rapid
(and possibly catastrophic) transition may
occur. It is important for managers to
understand this and assess the amount of
stress an ecosystem can sustain before it is
irretrievably damaged. Assessing ecosystem
health with respect to climate change is
complicated by our lack of understanding of
the effects of previous human interventions.
Ecosystems have already been considerably
altered by the cumulative effects of water-level
regulation, pollution, introduction of exotic
species, and resource exploitation, to name a
few. These effects may decrease our ability to
detect changes caused by climate change and
variability.
6.1 Chemical Stressors
The large algal mats that dominated Lake Erie
waters during the sixties and seventies have
disappeared with the introduction of, and
adherence to, strict phosphorus-loading
targets. Although control programs have
generally reduced nutrient concentrations in
the Lakes, high concentrations can still occur
locally in embayments and harbors, arising
STATE OF THE GREAT LAKES —1997
39
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Legend
I Navigation channel
I Potential loss of
nearshore habitat
Figure 12. Potential Loss of Nearshore Habitat in Lake St. Clair (due to a lowering of Lake levels)
as a Result of Climate Change, Based on a Doubling of Carbon Dioxide
Source: Lee, D., R. Moulton, and B. Hibner. 1996. Climate change impacts on western Lake Erie, Detroit River, and
Lake St. Clair water levels, report prepared for the Great Lakes-St. Lawrence Basin Project, 51pp.
from agriculture and urban sources (Figure 13).
Excessive algal growth due to high nutrient
concentrations leads to algal decomposition
and oxygen depletion. A shift in the makeup of
the ecological community then follows, favoring
species that benefit from excess nutrients,
reduced oxygen, and the reduced sunlight and
visibility conditions that are generated by
excess algal growth.
The impact of persistent toxic contaminants is
less visible and often shows no effect until the
contaminants are concentrated in the food
chain, beginning with algae and zooplankton.
Through the processes of biomagnification and
bioaccumulation, the impact of toxic chemicals
is greatest on animals at the top of the food
web such as predatory birds, fish, and
mammals, including humans. Effects seldom
result in acute symptoms or death at any level
within the ecosystem, but they include
impaired reproduction and reduced resistance
to disease. Toxic chemicals enter the
nearshore ecosystem via a number of routes,
including atmospheric deposition, pesticide
use, industrial discharge, municipal discharge,
storm runoff, and leaching from contaminated
sediments from both on shore and underwater.
Pesticides are an important part of Great
Lakes basin agriculture. These chemical
compounds are widely used for the control of
weeds, insects, and diseases that can reduce
production. The risk to wildlife and human
health of pesticide exposure is a matter of
public concern, and continued scientific
401
STATE OF THE GREAT LAKES—1997
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Total Phosphorus Concentrations
in the Great Lakes
J
Legend
0.002 - 0.004 ppm
0.005 - 0.009 ppm
10.010-0.014 ppm
10.015 ppm +
Year of Data Collection
Lake Superior 1991
Lake Huron 1994
Lake Erie 1995
Lake Ontario 1993
50
250 km
Figure 13. Total Phosphorus Concentrations in the Great Lakes
Source: Edsall, T. and M. Charlton. 1997. Nearshore Waters of the Great Lakes. (SOLEC 96 Background Paper)
research is necessary to characterize the
nature of any risk and help devise effective and
safe formulations and methods of use.
According to a report prepared by the World
Wildlife Fund, agriculture in the Great Lakes
basin uses an estimated 26 million kilograms
(58 million pounds) of pesticides annually.
Herbicides represent about two-thirds of the
pesticides applied, with corn and soybeans
receiving much of this amount. These
herbicides must be present in high
concentrations to be toxic to animals, but can
affect aquatic plants at lower levels. Direct
toxicity due to short exposures at high
concentration would be more likely to occur in
headwater reaches; whereas effects due to
chronic (longer-term at somewhat lower levels)
exposure would be more likely in the lower
reaches and in the nearshore waters.
The atmosphere is also an important and
sometimes predominant pathway for toxic
contaminants to the Great Lakes. The very
nature of the Great Lakes contributes to the
intensification of air-quality problems caused
by the industrial and urban heartland around
the lower Lakes. Emissions from cars and
trucks using the road network inside as well as
outside the Great Lakes basin are a significant
source of atmospheric pollutants. Pollution
sources of local atmospheric toxic substances
are fairly well-understood and are being
subjected to continuing abatement efforts.
However, as development around the Great
Lakes increases the number of local roadways
and traffic density, air quality declines.
Although 25-year trends in Ontario's air quality
show significant decreases in average levels of
a number of compounds (lead, carbon
monoxide, sulphur dioxide, total sulphur
STATE OF THE GREAT LAKES — 1997
41
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particles, nitrogen oxides), ozone pollution has
increased. Ozone, a by-product of nitrogen
oxide pollution, is a powerful lung irritant.
Local concentrations of ground-level ozone
and acid aerosols can be significantly higher
near the shorelines compared with those
measured at sites well inland. During the warm
season, the relatively smooth and cold
surfaces of the Great Lakes interact in varying
fashions with the air pollutants that move into
the basin or are produced locally. Ground-level
ozone tends not to deposit on lake waters, so it
travels further than would otherwise be the
case. On the other hand, airborne ammonia,
which normally neutralizes acid aerosols,
dissolves so well on the surface of water that
acid aerosols tend to persist longer. The Great
Lakes also develop local lake breeze
circulations, which can confine pollutants and
under the right conditions cycle them around
the lake shorelines. This limits dispersion and
creates a "pressure cooker" effect in which
greater concentrations of smog can form in
urban plumes.
In Ontario, the highest concentrations of
ground-level ozone are measured not
immediately downwind of cities as might be
expected, but at Long Point on the Lake Erie
shoreline, followed by stations near Lake
Huron. During smog episodes, acid sulphate
concentrations near Lake Erie have been
measured at more than twice the
concentrations observed inland, coupled with
the high levels of ozone. A similar pattern
occurs around all of the Great Lakes south of
Lake Superior; however, it is diminished by
distance from the main sources and modified
by the way the shoreline interacts with the
large-scale wind pattern.
This local pollution intensification is due to the
very existence of the Lakes and cannot be
changed. Abatement measures that would
produce adequate results at inland sites may
be insufficient near the shores or over the
Lakes. Work is under way to understand the
situation better through enhanced
meteorological models. Additionally, the
potential health impacts must be properly
assessed and communicated to the public.
People may have to be advised that the
summer air on a beach or in other recreational
areas can be worse than it would be in the city.
Nearshore regions encounter atmospheric
stresses which are most severe at local scales,
near urban areas for example. However,
atmospheric pollutants may be deposited on
the Lakes from sources large distances away
from the Great Lakes basin due to long-range
transport. Toxaphene, for example, has been
seen to arrive from areas in the southern U.S.
and Mexico where it was widely used in the
past (Figure 14). Five-day back trajectories are
shown for the five highest air concentrations of
toxaphene measured at Egbert, Ontario, during
a one year study in 1988/9. These air
trajectories arise from regions which have
known high historical use patterns as indicated
by the tonnages shown. This indicates that
toxaphene is still arriving in the Great Lakes
basin some ten years after its usage was
banned and points to the existence of the
'grasshopper effect', the revolatilization and
redeposition of old use pesticides. For many
past-use chemicals which are now banned or
restricted in North America, residual re-
emissions can be important sources of
contaminants to the lakes.
42
STATE OF THE GREAT LAKES—1997
-------
Figure 14. Five-day back trajectories for toxaphene measured at Egbert, Ontario.
Source: Hoff, R., D, Muir, N. Grift, and K. Brice. 1993. Measurement ofPCCs in Air in Southern Ontario, Chemosphere,
27, 2057-2062.
6.3 Biological Stressors
In terms of biological stress, the global transfer
of exotic organisms is one of the most
pervasive and perhaps least recognized effects
of humans on the world's aquatic ecosystems.
As illustrated earlier in this report, such
transfers lead to loss of species diversity and
to extensive alteration of native communities.
Decline and loss of species and genetic
diversity are critical aspects in the loss of
ecosystem integrity and the ability of ecological
communities to remain resilient during times of
environmental change. Genetic diversity within
species improves the odds that at least some
members of the population will have the genes
needed to survive a particular environmental
change.
Exotic species have affected the Great Lakes
aquatic ecosystem since the early 1800s. At
least 139 new organisms have become
established—42 percent are plant species, 18
percent are fish species, and 17 percent are
algae species. The remaining 22 percent are
made up of a variety of species, including
mollusks, crustaceans, and disease
pathogens.
It is useful to distinguish between the forces
that introduce exotic species into the Great
Lakes. Some exotic species are introduced
into the Great Lakes intentionally, for example,
the stocking of some non-native fish species
into the Lakes such as Pacific salmon, rainbow
trout, and brown trout; many more are
introduced unintentionally. Shipping activities
STATE OF THE GREAT LAKES — 1997
43
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alone are responsible for bringing 41 exotic
aquatic species to the Great Lakes, of which
63 percent arrived in ballast water, 31 percent
with solid ballast, and 6 percent on ship hulls.
Unintentional releases established 40 new
species in the Great Lakes, 30 percent of
which were plants that escaped from
cultivation. Unintentional releases also include
accidental release from fish culture activities
(19 percent) and aquarium holdings (17
percent). Seventeen organisms entered the
Great Lakes through canals, along railroads or
highways, or as deliberate releases.
Not all exotic species are invasive and
disruptive. Many are unable to compete with
native species or simply exist in balance with
native species. Some exotic species, however,
are invasive and destructive of native species
and communities. Invasiveness is usually
associated with unusual competitive
advantage, which may have evolved in the
place of origin or result from the absence of
predators or diseases of the organism in the
new location. Moreover, native species need
time to adapt to competition from newly arrived
organisms. This may, however, take a very
long time, and the native species may be
unable to adapt. Each exotic species exists as
a natural component of a natural ecosystem in
the waters of its homeland. In a new location, it
may be free of the natural checks established
through long periods of evolutionary
development and be able to invade and take
over large areas. As they do, they cause
drastic changes to food chains and habitats
that are essential to our native plant and
animal communities.
An additional factor in the rapid spread of
invasive exotic species is the disruption of the
habitats that support native species. Natural
disturbances are a normal part of the
ecosystem and are important to its long-term
balance. However, human development of
agriculture, industry and communities causes
disturbance of large-scale areas in relatively
brief time frames, which do not allow the native
species and biological communities to adapt.
Changes in hydrology, water chemistry, and
water temperature are examples of
disturbances that have favored exotic species.
Another category of biological stress is
excessive harvest of renewable resources.
This directly affects biological integrity and can
also create conditions favoring invasive exotic
species. Exotic species compete for nutrients
and space with native species, often moving in
when an ecosystem has been disturbed and
before native species have time to recover. For
example, excessive harvesting caused the
depletion of top native predator fish in the
Great Lakes, paving the way for explosive
growth of non-native alewife populations.
Another invasive fish species is carp, which
may have been aided by depletion of lake
sturgeon. The lake sturgeon, which does not
reproduce until it is about 25 years old, was
one of the first species to fall victim to this type
of stress. Annual catches in Lake Erie's U.S.
waters fell from an all-time high of 2.1 million
kilograms in 1885 to about 13,000 kilograms in
1917. Thereafter, reported catches never
exceeded 10,000 kilograms, and after 1966,
the catch fell to zero. Increased awareness of
the consequences of overfishing, has led to
fisheries management efforts to avoid the
recurrence of such devastation to other Great
Lakes fish populations.
One final example of biological stress on the
nearshore ecosystem is microbial
contamination (micro-organisms include
bacteria, fungi, microscopic algae, protozoa,
and viruses). The human population in the
Great Lakes basin produces large amounts of
liquid wastes (sewage), which must be
rendered harmless by processes in sewage
treatment plants. In spite of technology that
makes it possible to perform high levels of
sewage treatment, large amounts of pollutants
are still discharged into Great Lakes waters.
This is especially true in areas that have
combined sanitary and storm sewer systems.
Storm drains are fed into the same pipes that
carry household sewage and industrial wastes.
Combined systems saved costs for
44
STATE OF THE GREAT LAKES—1997
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municipalities at the time of construction
because separate sanitary sewers were not
built. However, the greater volume that the
sewers are required to carry during periods of
heavy rainfall or snowmelt frequently exceeds
the capacity of the system, causing overflow
that bypasses the treatment plant and
discharging untreated sewage into the
receiving waters. Wastes from farm animals
and even wildlife can also be sources of
pathogens.
7. Lake by Lake
As described in the 1995 State of the Great
Lakes report, climate, soils, and
topography vary widely throughout the Great
Lakes basin. In the north, the climate is cold,
and the terrain dominated by a granite bedrock
known as the Canadian (or Laurentian) shield.
Coniferous forests dominate the vegetated
landscape, growing on a generally thin layer of
acidic soils. In the south, the climate is
significantly warmer, and the terrain flatter with
clay, silt, and sand, forming many fertile areas
mixed in places with gravel and boulders.
These differences in physical form represent
only the first in a long list of factors that make
each Great Lake unique. Plant species differ;
animal species differ; and the concentration of
human settlement varies widely throughout the
basin. From the relatively low-density
populations along the northern coast of Lake
Superior to the high-density areas found in
coastal cities such as Toronto and Chicago,
humans play a large role in dictating nearshore
ecosystem health on each Lake.
Using the following words in the statement of
purpose in the Great Lakes Water Quality
Agreement, the U.S. and Canada agreed to
protect their shared treasure:" to restore and
maintain the chemical, physical, and biological
integrity of the waters of the Great Lakes Basin
Ecosystem." The Agreement contains many
provisions to accomplish this, but a key aspect
is the commitment to coordinate restoration of
beneficial uses. A major component of this is
the development of plans at two geographic
scales. For designated geographic Areas of
Concern (AOCs), where beneficial uses are
impaired, there are Remedial Action Plans
(RAPs). At the lakewide scale, Lakewide
Management Plans (LaMPs) are being
developed to address restoration of beneficial
uses.
The U.S. and Canadian governments are
working cooperatively to restore each of the
remaining 42 (of the original 43) AOCs, so
identified because one or more of 14 beneficial
uses have been impaired. Local involvement is
integral to the success of the remediation
effort, and communities throughout the basin
are working together in the cleanup process
(through RAPs) to restore and protect
environmental quality in these areas. There are
11 AOCs on the Canadian side of the Lakes,
26 AOCs on the U.S. side of the Lakes, and 5
AOCs in connecting channels (Figure 15).
Restoration of beneficial uses within the AOCs
is the primary mission of RAPs and is an
essential step in restoring the integrity of the
Great Lakes basin ecosystem. Many of these
AOCs have received decades of abuse.
Identifying the problems, and planning and
implementing the remedial strategies
necessary to restore the beneficial uses in
these areas can also take many years. One
AOC, Collingwood Harbour, Ontario, has had
its beneficial uses restored and is no longer
listed as an AOC. The status of the beneficial
use impairments for the AOCs is shown in
Figure 16 (on pages 68-69).
LaMPs for Lakes Ontario, Erie, Michigan, and
Superior are currently being developed.
Individual LaMP programs are unique to each
Lake and designed to deal with the issues and
concerns of the agencies and publics involved.
LaMPs are broader in scope than RAPs and
can plan for lakewide load-reduction targets
that have not been specified by RAPs. A LaMP
for Lake Huron is scheduled to begin in 2000.
STATE OF THE GREAT LAKES —1997
45
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Areas of Concern In the
Great Lakes Basin
x/
" Lawrence River
(Massena)
Milwaukee Estu;
Waukegan Harbor
Grand Calumet Rivei
Legend
• Canada
• U.S.A.
if Delisted AOC
A Connecting
Channels
Figure 15. Areas of Concern in the Great Lakes Basin
Source: Geomatics Unit, Environment Canada, Ontario Region.
All the Lakes have some restrictions on fish
consumption in order to protect the health of
humans. Indicator species for coldwater fish
include lake trout, and for warmwater fish,
smallmouth bass, walleye, and yellow perch.
The following sections of this report take a
closer look at the nearshore ecosystems in
Lakes Superior, Michigan, Huron, Erie, and
Ontario.
7.1 Lake Superior
Lake Superior is the deepest (with an average
depth of 147 meters, or 483 feet)2, the coldest,
and the cleanest of the Lakes in the Great
Lakes ecosystem. It has the largest surface
area of any freshwater lake in the world,
encompassing 82,100 square kilometers
(31,700 square miles), and a shoreline of
4,385 kilometers (2,726 miles). The Lake also
holds more water than all the other Great
Lakes combined and ranks third in volume
when compared with all other freshwater lakes
on Earth.
2AII length, depth, area and volume references in section 7 of the 1997 State of the Great Lakes report are from the
following source: United States Environmental Protection Agency and Government of Canada. 1995. The Great Lakes:
An Environmental Atlas and Resource Book. ISBN 0-662-23441-3. Chicago, Illinois and Toronto, Ontario.
46
STATE OF THE GREAT LAKES—1997
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Because of the Lake's large surface area and
position at the headwaters of the Great Lakes
ecosystem, rain and snowfall represent the
largest sources of water to the Lake. The 335
tributary rivers and streams that drain into the
Lake from the surrounding watershed
represent the second largest source of water.
Canada's Nipigon River is the largest tributary
entering the Lake, and the second largest is
the St. Louis River, which enters the Lake at
Duluth. Water leaves the Lake through
evaporation and regulated discharge via the
St. Marys River. One result of this combination
of physical characteristics is that a drop of
water entering the Lake tends to stay in the
Lake for a long time—between 173 and 191
years. This is also known as retention time.
The geology of the Lake Superior watershed is
dominated by the outcrops of the Canadian
Shield, rocks from the most ancient portions of
the North American continent. These durable
rocks form the northern Minnesota and
Canadian shorelines, which are typified by
prominent cliffs and rocky coastlines. Southern
shore areas exhibit relatively well-developed
beaches, dune fields, and wetland
environments.
Development pressures are not as intense in
the Lake Superior basin as they are in the
other Great Lake basins, and the land-use
activities in the Lake basin have had a
relatively low impact on Lake Superior's
nearshore ecosystem. Approximately 95
percent of Lake Superior's 127,700 square
kilometer (49,300 square mile) drainage basin
is forested, and the remaining 5 percent is split
between agriculture, urban/industrial, and other
land uses. With less than 2 percent of the
entire Great Lakes basin population
(approximately 610,000 residents), the Lake
has been able to avoid many of the problems
that go hand in hand with population
pressures.
Forestry, mining, shipping, and tourism/
recreation are the four industries that form the
mainstay of economic activity in the region.
Residents of the Lake Superior basin have
been affected by a long-term economic
decline, and the result has been migration out
of the basin. In 1970, 680,000 people lived
within the basin, but by 1990/91, 70,000
people had left. On the U.S. side of the Lake,
the relatively poor economic health of the area
is reflected in depressed wage levels and an
unemployment rate that is above the state
average. The economy of the Canadian side of
the basin is somewhat stronger, but is still
weaker than in the rest of the province.
However, despite the relatively weak basin
economy and overall population decline, two
significant trends are distinguishable: (1)
Populations are expected to increase in the
two largest urban areas within the basin,
Duluth-Superior and Thunder Bay (both of
which have strong local economies). (2) The
number of second-home residents in the basin
is rising, bringing both opportunities and
challenges.
Although Lake Superior is relatively clean,
there are localized hotspots where point
source pollution has had an impact on the
ecosystem. The seven AOCs identified on the
Lake are Peninsula Harbour, Jackfish Bay,
Nipigon Bay, Thunder Bay, St. Louis River,
Torch Lake, and Deer Lake. Non-point source
pollution deposited from the atmosphere is a
proportionately large source of pollution in
Lake Superior, and it has been determined that
non-point sources actually have a bigger
influence over nearshore water quality in the
Lake than do point sources. For example,
atmospheric sources account for 93 percent of
STATE OF THE GREAT LAKES—1997
47
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total mercury loadings and 98.8 percent of
PCBs.
There are consumption advisories for
coldwater fish species, but these occur mainly
with respect to the fish from the eastern end of
the Lake (in the open waters from Sewell Point
to Batchawana Bay), as well as in the waters
of Thunder Bay's outer harbor. The principal
contaminant causing these consumption
restrictions is toxaphene, and dioxins are a
concern in specific locations, such as Jackfish
Bay. Although information on contaminants in
indicator species is available only for certain
sites, the only restriction on consumption of
warmwater species relates to the walleye from
Schreiber Point to Sewell Point. The
contaminant causing the restriction is mercury.
In Lake Superior, the lake trout fishery is now
maintained through natural reproduction of wild
fish. This represents the first successful
rehabilitation of lake trout stocks in the Great
Lakes. Lake whitefish are abundant and
support a productive fishery. Lake herring
numbers are recovering strongly, whereas
brook trout and lake sturgeon populations have
not recovered from earlier declines and are still
at low levels. Introduced species of trout and
salmon support a stable fishery, but rainbow
smelt are reduced from earlier levels of peak
abundance.
Overharvesting is only one factor causing fish
populations to decline. Exotic species such as
sea lamprey and ruffe also contribute to the
decline. Sea lamprey have been reduced to
about 10 percent of their former peak
abundance through the sea lamprey control
program, thus saving some stocks of lake trout
in Lake Superior. However, sea lamprey
require continual control in order to increase or
even sustain lake trout populations. Ruffe is an
exotic fish species that has no commercial or
sports value. It was introduced into Duluth
Harbor from the ballast water of transatlantic
cargo vessels. The ruffe has steadily spread
through the nearshore waters, is increasing in
abundance, and competes with perch and
other native species for food and habitat.
Lake Superior's coastal wetlands are in
comparatively good condition. Although there
are no comprehensive estimates of coastal
wetland losses for Lake Superior, it is clear
that coastal wetlands on the Lake are
comparatively less affected by human
stressors than those of the other Great Lakes.
Some local areas are degraded and regulation
of lake levels is having some negative effect
lakewide.
The north shore of the Lake is a high energy
environment with few areas of sediment
deposition. As a result, coastal wetlands are
rare, and those that do occur are restricted to
the large sheltered embayments of Goulais
Bay and Batchawana Bay in the northeast, and
Thunder Bay, Black Bay, and Nipigon Bay in
the northwest. To date, approximately 915
hectares (2,287 acres) of coastal wetlands
have been evaluated for quality in Canada; but
at least 3,500 hectares (8,750 acres) have not.
Along the southern shore of Lake Superior,
coastal wetlands are larger and more
numerous than those found along the north
shore. The shoreline is more complex, and
many river mouths provide shelter from wind
and wave action, thereby allowing wetlands to
develop. Coastal wetlands occupy a total of
21,357 hectares (53,393 acres) along the
south shore of Lake Superior. In Wisconsin,
many large wetlands remain in relatively
pristine condition, the largest of which is the
3,850 hectare (9,510 acre) Chequamegon
wetland on the Bad River Indian Reservation,
Lakewide, 41 fish species have been identified
that use coastal wetlands for spawning,
nursery, and feeding habitats.
Water-level regulation is the most widespread
stressor on coastal wetlands on Lake Superior;
however, other stressors affect wetlands on a
site-specific basis. Nutrient enrichment, toxic
contamination, recreational use, and shoreline
48
STATE OF THE GREAT LAKES—1997
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development all act as site-specific stressors
to coastal wetlands located on the Lake.
The health of Lake Superior's nearshore
terrestrial ecosystems is better than the health
of the other four Lakes, and fewer shoreline
species and communities have been lost than
in the other Lakes (see Table 8). Shoreline
development activities are limited (because of
lower population levels as well as the fact that
the coastal substrate is primarily bedrock and
cobble shore); therefore, shoreline processes
are not as extensively interrupted by armoring
as is the case with other Lakes, A good
representation of Lake Superior's nearshore
terrestrial biodiversity can be found in the
lakeshore parks and protected areas. Progress
has been made in protecting areas of
particularly high biodiversity through the
creation of new parklands or other protected
areas, the development of land-use policies
that will result in improved protection of the
significant elements within these priority areas,
and private stewardship initiatives. This
progress has been rated as mixed/improving in
the background paper "Land by the Lakes:
Nearshore Terrestrial Ecosystems."
7.2 Lake Michigan
Lake Michigan is the only Great Lake entirely
within the U.S. The Lake and its basin's land
area are each the third largest of the Great
Lakes and their basins, respectively. It is the
fourth largest freshwater lake in the world in
terms of area, and the fifth largest in terms of
volume. Water retention time in the Lake is
estimated at approximately 100 years, and the
average depth in the Lake is 85 meters (279
feet). Census data for 1990 indicate a basin
population of just over 10 million, most of
which is located in the densely populated
southern portion of the basin.
Lake Michigan may be the most diverse of any
of the Lakes. Its shoreline changes continually
from one major landform to another, with each
major type extending for hundreds of miles. It
has lakeplains, high clay bluffs, low erodible
bluffs, vast dune fields, rocky cliffs, glacial drift
bluffs, sand ridge shores, and clay/pebble
embayments flanked by ancient ridges.
Landforms in the basin vary from relatively
high relief areas in the northwest to low relief
plains in the central and southern portions of
the basin. One of the most impressive features
of the basin's nearshore is the expanse of
sand dunes along parts of the eastern shore.
Lake Michigan coasts also contain about 40
percent of all U.S. Great Lakes coastal
wetlands, which are equally as diverse as the
shoreline.
There are 411 coastal wetlands covering a
total area of almost 49,000 hectares (121,000
acres). Most of these wetlands are
concentrated along the rivers emptying into the
Lake along Michigan's western shore and in
Green Bay (some of the finest examples of
Great Lakes marshes are in Green Bay and
along the eastern side of the Door Peninsula).
However, south of Sturgeon Bay all the way to
Chicago, wetland development has been very
limited because most of the shoreline consists
of high bluffs with narrow, high energy beaches
and few unmodified river mouths. At all river
mouths urbanization has eliminated the
wetlands. Small, remnant wetlands can be
found south of Chicago and around the bottom
of the Lake. In the Calumet area, some of
these are being restored and reconnected to
the Lake. From Northern Indiana and
continuing into Michigan, massive coastal
dunes flank the shoreline for about 370
kilometers (230 miles). These dunes run
without interruption, except for river valleys,
some cities, and roads, along the entire shore
to heights of 100 meters (328 feet) and
breadths up to 1.5 kilometers (nearly a mile).
They are extensively urbanized with summer
homes and permanent residences along many
stretches, often very close to the shore. North
of Leland, through the Traverse Bays and
continuing north to the Straits of Mackinac, the
Lake Michigan shore changes again into rocky
cliffs and bluffs, cobble beaches, and
occasional small embayed wetlands. From the
STATE OF THE GREAT LAKES — 1997
49
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Straits westerly, the Michigan shore becomes
distinct again, with low relief, multiple sand
ridges being interrupted by shallow, sheltered
bays.
The northern part of the Lake Michigan
watershed is climatically cooler, covered with
forests, and has a relatively scattered
population (except for the Fox River Valley).
The southern, more temperate portion of the
basin is heavily populated with areas of intense
urbanization, industrial development, and
productive farmland.
Water quality in the basin varies widely, from
nearly pristine in some northern areas to
seriously contaminated in others. In the heavily
populated and industrial southern tip of the
Lake, nearshore water quality is severely
diminished. The cause of this poor water
quality originates almost entirely from urban
sources. Direct stormwater flows as well as
discharges from storm sewers into streams
and directly in to the Lake contribute sediment,
nutrients, pesticides, herbicides, oils, and
heavy metals. A recent evaluation of the
southeastern basin revealed that of 210 stream
miles assessed, 186 were considered
unsuitable for aquatic life. Contaminated
sediments in rivers and harbors remain a
serious problem in the area.
Ten AOCs have been identified on Lake
Michigan: Manistique River, Lower Menominee
River, Lower Green Bay and Fox River,
Sheboygan River, Milwaukee Estuary,
Waukegan Harbor, Grand Calumet River/
Indiana Harbor Ship Canal, Kalamazoo River,
Muskegon Lake, and White Lake. Contributors
of point source pollution are primarily paper
mills in the northern basin and steel-related
industries in the south. In the past two
decades, however, implementation of pollution-
control policies has dramatically reduced the
amount of pollution being discharged from
these sources and, currently, non-point
pollution sources are the primary cause of
degraded water and air quality in the basin.
Substantial numbers of stocked, breeding-age
lake trout are present in the Lake. Spawning
and fry production by stocked fish have been
recorded at several locations, and wild yearling
and older lake trout have also been found in
the Lake; however, substantial numbers of
adult wild lake trout have not been produced.
Pacific salmon abundance has been sharply
reduced compared with the peak levels
reached between the 1970s and middle 1980s,
the cause of which is not completely
understood. The biomass (a measure of
abundance expressed as weight) of each of
the three major forage fish (alewife, rainbow
smelt, and slimy sculpin) in Lake Michigan has
also changed significantly since the 1970s.
Alewife constituted more than 80 percent of the
biomass in catches in the 1970s but declined
to about 10 percent in the middle 1980s
through the 1990s. The biomass of rainbow
smelt decreased from between 15 and 20
percent in the 1970s and early 1980s to less
than 10 percent in the middle 1980s and
1990s. Slimy sculpin abundance peaked in the
late 1970s, but declined in the 1980s and
1990s to less than 20 percent of peak 1970s
levels, probably in response to predation by
trout, burbot, and introduced salmon.
The predominant development trend in the
Lake Michigan basin is continued low-density
sprawl. This population shift to the urban
periphery and suburbs, together with the
demand for low-density development,
consumes vast amounts of agricultural lands
and open space. Counties in the eastern Lake
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STATE OF THE GREAT LAKES—1997
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Michigan basin, for example, experienced
reductions in farmlands acreage of 7 percent to
more than 15 percent from 1982 to 1992,
pushing the average for that region in excess
of the average loss rates for the State of
Michigan during that period (7.8 percent). On
the western side of the basin, the same trend
is apparent. Wisconsin coastal counties on
Lake Michigan showed a net gain of 41,584
housing units from 1990 to 1995, nearly half of
which were in communities bordering the
shoreline.
The largest concentration of steel production in
North America is located near the southern tip
of Lake Michigan. When fabricating and
warehouse facilities are included, the sprawling
scale of steel production occupies thousands
of nearshore acres and, in some areas, unique
dune ecosystems. Steel-making has been a
historical polluter of water and soil, and the
Lake Michigan steel-making legacy has
generated tons of pollutants, some of which
are still present in contaminated sediments in
nearshore waters and soil within plant
boundaries.
The Lake Michigan basin economy supports
more than twice as many jobs as the next
largest economy among Great Lakes basins
(Lake Erie). The basin has the most
manufacturing jobs among the individual Great
Lakes basins, but employment in this sector
has been declining while employment in the
service sector has been rising. Between 1970
and 1990, the service sector in Lake
Michigan's drainage basin grew nearly 100
percent, and today, over 2 million service
sector jobs are located there.
Fish consumption advisories are in effect for
lake trout, brown trout, rainbow trout, coho
salmon, Chinook salmon, whitefish, walleyed
pike, perch, smelt, carp, and sturgeon. Large
lake trout and brown trout should not be eaten
at all, whereas it is recommended that
consumption of the others be limited. PCBs are
the principal contaminants causing the
consumption advisories.
The status of nearshore terrestrial ecosystem
health in Lake Michigan reflects the impact of
ongoing development pressures on the basin
(see Table 8). The health of shoreline species
and communities has been rated as mixed/
deteriorating, and the effect of shoreline
armoring on natural shoreline processes is
also mixed/deteriorating. Biodiversity in the
Lake Michigan basin varies with location, and
while representation of biodiversity in
lakeshore parks and protected areas is stable,
efforts to designate additional biodiversity
investment areas have been improving.
7.3 Lake Huron
Renowned for its more than 30,000 islands
and its summer cottages, Lake Huron is one of
the least developed of the Great Lakes, and is
second only to Lake Superior in area. When
island shorelines are included, Lake Huron has
the longest shoreline of the Great Lakes. It is
the third largest freshwater lake in the world in
terms of area, and the sixth largest in volume;
it boasts the largest island (Manitoulin) of any
freshwater lake on Earth. The retention time for
water in Lake Huron is 22 years, and the
average depth is 59 meters (195 feet).
The U.S.-Canada border divides Lake Huron
almost in half. The Canadian portion of the
Lake, including Georgian Bay, is wholly in the
Province of Ontario. The U.S. portion is located
entirely within the State of Michigan. The
STATE OF THE GREAT LAKES —1997
51
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drainage basin on the Ontario side (86,430
square kilometers or 33,500 square miles)
covers twice the area, has approximately five
times the shoreline, and roughly 300,000 fewer
residents than in Michigan. On both sides of
the border, the population density is low
(approximately 39 persons per square
kilometer, or less than 100 persons per square
mile), with Michigan's Saginaw Bay area
representing the only large urbanized center
on the Lake Huron shore.
The 134,100 square kilometer (51,700 square
mile) drainage basin of Lake Huron is
predominantly forested (66 percent), with
lesser amounts of agricultural land (22
percent), residential and industrial land (10
percent), and other land uses (2 percent). The
southern portion of the watershed is developed
to a greater degree than the northern portion,
although residential and agricultural
development dominates in both areas.
Pollution is most severe in the waters at, and
adjacent to, urban and rural settlement areas.
Four AOCs had been identified on Lake Huron
(Saginaw River/Bay, Collingwood Harbour,
Severn Sound, Spanish Harbour). Collingwood
Harbour has had all beneficial uses restored,
as a result of the efforts of those involved in
the remediation. It has been delisted and is no
longer classified as an AOC. Of the remaining
three AOCs, Saginaw Bay presents by far the
largest problem in terms of remediation.
The wetlands of Lake Huron are generally
smaller but more abundant than those in the
southern Great Lakes and over half are
wetland complexes. Marshes and swamps are
equally dominant, and many have significant
fen components. They also have more
complex vegetative communities than those in
the southern Great Lakes. Wetlands along the
Canadian shore of Lake Huron are common in
the sheltered embayments and creek mouths
and in the lees of large islands. Although an
accurate estimate of coastal wetlands in this
area is not available, 7,159 hectares (17,900
acres) of wetlands have been evaluated for
quality on the Canadian side of the Lake.
There are an estimated additional 16,200
hectares (40,500 acres) of coastal wetlands on
the Michigan side of the Lake. As a result,
Lake Huron's Michigan coast has nearly 37
percent of all coastal wetlands found in the
state of Michigan.
Along the Canadian shore of Lake Huron, loss
of wetland habitat on a large scale has not
occurred because most of the shoreline is
sparsely populated. Losses tend to be
concentrated around the small urban centers
that dot the shore. Within the last 10 years,
there has been incremental and site-specific
loss of wetland area from agricultural
encroachment and cottage development.
Over 40 species of rare plants, 5 significant
reptile species, and 59 fish species use the
coastal wetlands of Lake Huron. At least half of
those fish species are permanent residents in
the wetlands, whereas the remainder use them
on a temporary basis for feeding, shelter,
spawning, nursery, dispersal of young, and
migratory wandering.
The fish community in Lake Huron is
recovering, but remains unstable after decades
of being overharvested and being subjected to
the effects of introduced species. Modest
numbers of stocked lake trout are reproducing
in the Lake, and populations of whitefish are
more abundant than at any other time in this
century. Walleye and yellow perch are once
again abundant. Rainbow smelt and alewife
populations are currently stable, but have been
reduced in comparison with former peak levels
52
STATE OF THE GREAT LAKES—1997
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in the 1970s. In the 1980s, sea lamprey
increased in abundance in the northern end of
the Lake, imposing high mortality on lake trout
and reversing gains that had been made in
lake trout restoration in that area.
Where data exist, limited consumption
restrictions are in place for lake trout (a
coldwater species) down the length of the
eastern shore of Lake Huron, from Fitzwilliam
Island to north of Grand Bend. PCB is the
principal contaminant of concern causing these
consumption advisories. The only restriction on
eating warmwater/coolwater fish is on
smallmouth bass because of mercury
contamination.
Of the four indicators used to assess
nearshore terrestrial ecosystem health in each
Lake, Lake Huron is in the middle when
compared with the other four Great Lakes (see
Table 8). Loss of shoreline species and
communities continues, but there is evidence
that improvements have slowed down the rate
of shoreline armoring and thus slowed down
the rate at which shoreline processes are
interrupted. Representation of biodiversity in
lakeshore parks and protected areas is rated
as mixed/improving, but gains in biodiversity
investment areas is described as mixed/
deteriorating.
7,4 Lake Erie
Lake Erie is the fourth largest of the Great
Lakes in surface area (25,700 square
kilometers, or 9,910 square miles) and the
smallest in volume. As the shallowest of the
Lakes, the retention time of water in Lake Erie
is only 2.6 years. About 90 percent of the
Lake's total inflow of water comes from the
upper Great Lakes, the St. Clair River, and
Lake St. Clair through the Detroit River. The
remaining portion comes from precipitation and
tributaries. The Niagara River and shipping
canals serve as Lake Erie's outlets and drain
into Lake Ontario.
Lake Erie, together with the St. Clair River,
Lake St. Clair, and the Detroit River, has a
watershed of 78,000 square kilometers (30,140
square miles). Most of this watershed is
agricultural (59 percent), and the remaining
land is forested (17 percent), residential or
industrial (15 percent), or under other land
uses (9 percent). Several large sand spits
project into Lake Erie, creating valuable
habitats. These include Long Point, Turkey
Point, Rondeau Peninsula, Point Pelee, and
Presque Isle. The lake basin can be naturally
divided into three sub-basins: the western
basin (to the west of Point Pelee), the central
basin (between Point Pelee and Long Point),
and the eastern basin (to the east of Long
Point)—the deepest portion of the Lake.
Of all the Great Lakes, Lake Erie is exposed to
the greatest stress from both urbanization and
agriculture. The Lake Erie basin has the
largest percentage of land use in agriculture of
any lake basin, but agriculture is experiencing
intense competition from other land uses,
especially from urban sprawl and scattered
rural development.
The economies of the Lake Erie basin are
markedly different in their range and type.
They include the Detroit urban-industrial
complex, rural agricultural villages, commercial
and recreational fisheries, and the water-based
cottage and recreational industry. Along the
shoreline itself, the economy is generally
driven by recreation and tourism, including
cottages, marinas, and fishing. Lake Erie is the
STATE OF THE GREAT LAKES —1997
53
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most biologically productive of the Great Lakes,
and its fishing industry is worth approximately
Cdn $100 million, of which $40 million is for
yellow perch alone.
The total population (Canada and the U.S.
combined) within the Lake Erie basin is
approximately 13 million, of which nearly 86
percent is on the U.S. side. Over the past
decade the population on the U.S. side has
been declining, while Ontario's population in
Lake Erie's basin has remained stable. The
greatest impacts on the Canadian side of Lake
Erie have been through growth and expansion
of urban areas along streams and rivers, such
as the Grand River. Urban development has
affected the nearshore by causing erosion,
increasing sedimentation, and adding
pollutants. Sewage, treated wastewater, and
stormwater issues are also high on the list of
detrimental environmental impacts within the
Lake Erie nearshore. The major causes of
these problems are not only the increased
residential development but also the
conversion of seasonal shoreline cottages to
permanent residences that use private septic
systems.
Although the Lake Erie basin is the most
densely populated and intensively farmed, and
the Lake receives large quantities of pollution,
it has been mitigated by sedimentation of algae
and fine soil particles from soil erosion, both of
which tend to adsorb pollutants from the water
(then settle at the bottom and become buried).
Additionally, Lake Erie's short retention time
also accounts for the lower pollution levels
(more pollutants flow through to Lake Ontario).
Accordingly, the water and fish in Lake Erie
have shown low concentrations of toxic
contaminants. Seven AOCs have been
identified on Lake Erie proper: River Raisin,
Maumee River, Black River, Cuyahoga River,
Ashtabula River, Presque Isle Bay, and
Wheatley Harbour with contaminated
sediments having an effect at all seven.
However, because of its shallow depth, relative
warmth, and the high fertility of the soils in its
basin, Lake Erie is more eutrophic than the
other Great Lakes and allows bacteria to thrive
during the warm summer months. Beaches all
along the shoreline have experienced high
bacterial levels leading to closures, but the
beaches in the western and central lake basins
are particularly affected.
Although investment in municipal and industrial
waste treatment, and programs to control
agricultural land runoff have achieved excellent
results in nutrient management, the near total
removal of native vegetation from the basin
and the severe exploitation of fisheries
followed by exotic species invasions have
devastated the original aquatic community of
the Lake. While some recovery may be in
sight, the long-term impact of exotic species,
such as zebra mussels, is unknown. Although
mussels have increased water clarity by
approximately 75 percent between 1988 and
1991, their feeding habits have led to large
changes in the food web, which may result in
undesirable changes in fish species
populations. They are also suppressing and
may be completely destroying populations of
native mussels.
The largest concentration of coastal wetlands
occurs along the shallow western basin of the
Lake, fringing the low-lying shorelines and
estuaries in Michigan and Ohio. The U.S.
shoreline of the central and eastern basin
consists predominantly of bluffs, therefore
limiting wetlands to river mouths and to
Presque Isle (a 10 kilometer, or 6.3 mile, sand
spit). There are 87 wetlands along the U.S.
shoreline, encompassing more than 7,937
hectares (19,842 acres). Most of the wetlands
have been diked and are hydrologically
isolated from the Lake. Fewer but more
extensive wetlands are nestled behind the
large sand spits along the north shore of Lake
Erie in Ontario and at river and creek mouths.
Along the Canadian shoreline are 31 wetlands
covering 18,866 hectares (47,165 acres). They
range in size from 3 to 13,465 hectares (7.5 to
33,663 acres), and over half are wetland
complexes consisting mostly of marshes with
54
STATE OF THE GREAT LAKES—1997
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some swamp and rare fen and bog
components.
The coastal wetlands of Lake Erie support the
largest diversity of plant and wildlife species in
the Great Lakes. The moderate climate of Lake
Erie and its more southern latitude allow for
many species not found along the northern
Great Lakes. Many rare species of plants can
be found in Lake Erie's coastal wetlands, and
at least 37 significant plant species are found
there. The wetlands are also important for fish
production because they provide spawning and
nursery habitat for many wetland-dependent
species, cover for juvenile and forage fish, and
feeding areas for predator fish. Forty-six
species of fish have been captured in Lake
Erie wetlands, and an additional 18 species
captured in open water are known to use these
wetlands during some part of their lives.
A comparison between the current Lake Erie
fish community and the historical community
shows that impairment has occurred and is
continuing. The status of 34 species of Lake
Erie fish are rare, threatened, endangered,
extirpated, extinct, or of special concern.
Stocked lake trout and coho salmon are not
reproducing successfully, and once-abundant
levels of forage fish species (such as rainbow
smelt, spottail shiners, emerald shiner, gizzard
shad, and alewife) have declined. Lake
whitefish are continuing to show signs of
recovery. Walleye and yellow perch are
intensively managed to provide productive
recreational and commercial fisheries in the
U.S. and Canada.
Lake trout are limited to the eastern basin of
Lake Erie because it is deeper and cooler.
PCB levels have led to a "limited" consumption
advisory for lake trout from Long Point Bay
eastward. No consumption restrictions are in
effect for any of the warmwater/coolwater
indicator fish species of any size in Lake Erie.
Over the past 10 years, 25 navigational areas
on or near Lake Erie have been dredged. In 12
of these areas, the dredged material has, at
some time, been required to be disposed in a
confined disposal facility. Dredged materials
from seven AOC sites currently require
confined disposal; these sites include the
Detroit and Rouge Rivers, River Raisin, and
Maumee River in the western basin, and the
Ashtabula River, Cuyahoga River, and Black
River in the central basin. PCBs are the most
commonly identified contaminant that
necessitates the confined disposal of dredged
material.
The overall health of the nearshore terrestrial
ecosystem in Lake Erie's basin has been given
one of the lowest ratings of all the Great Lakes
(see Table 8). All four indicators used to
assess nearshore terrestrial health have been
rated as mixed/deteriorating or poor. Shoreline
species and communities have been lost and
this trend is continuing; many shoreline
processes have been interrupted by armoring.
7.5 Lake Ontario
Lake Ontario ranks as the 12th largest lake in
the world, although its surface area of
approximately 18,960 square kilometers (7,340
square miles) makes it the smallest of the
Great Lakes. Its drainage basin is 64,030
square kilometers (24,720 square miles) and is
dominated by forests (49 percent) and
agriculture (39 percent). Approximately 7
percent of the basin is urbanized. Water levels
of the Lake are controlled by dams and locks in
the St. Lawrence Seaway along the St.
Lawrence River. Nearly 85 percent of the Lake
perimeter is characterized by regular (nearly
straight) shorelines sloping rapidly into deep
water.
Lake Ontario can be divided into two distinct
parts. The main basin reaches a maximum
depth of 244 meters (802 feet) and is bounded
by the Niagara Peninsula at its west end and
the Mexico Bay shoreline in the east. The
Kingston basin is much shallower and smaller
than the main basin; however, the irregular and
highly convoluted shoreline of the Kingston
STATE OF THE GREAT LAKES — 1997
55
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basin accounts for more than 50 percent of
Lake Ontario's total shoreline. The shoreline
extends for 1,146 kilometers (730 miles), with
many embayments and peninsulas in the
eastern third of the Lake. The only islands are
those near the outlet at the eastern end of the
Lake, and Toronto Island.
Wetlands are most abundant in the eastern
portions of the Lake. They occur at river
mouths, embayments, and behind bars and
barrier beaches. In total, 17,607 hectares
(44,018 acres) of wetlands have been
identified along the shores of Lake Ontario.
Dominant plants are often invasive species
(introduced or native), such as purple
loosestrife, eurasian water-milfoil, reed canary
grass, and hybrid cattail. Despite this, 17 rare
species of plants have been found in Lake
Ontario's coastal wetlands.
Sixty-eight species of fish use coastal wetlands
of Lake Ontario, two-thirds of which are
permanent residents. The other third use them
on a temporary basis for spawning, nursery, or
feeding.
The wetlands of Lake Ontario have suffered
severe loss over the last two centuries, mainly
through agricultural drainage and urban
encroachment. Between 1789 and 1979, an
estimated 1,518 hectares (3,795 acres) of
coastal marsh were lost between Toronto and
the Niagara River. That total represented
between 73 and 100 percent of the original
marsh along these shores. Along the entire
U.S. shore, wetland losses have been
estimated at nearly 60 percent. Most of the
losses are attributable to the heavily populated
areas surrounding Oswego and Rochester.
A major source of stress to all coastal wetlands
in Lake Ontario is water-level regulation. Water
levels have been regulated in the Lake since
the construction of the St. Lawrence Seaway in
1959. Prior to regulation, the range of water-
level fluctuations during the 20th century was
about 2 meters (6.5 feet). Between 1960 and
1976, this range was reduced slightly. Since
1976, however, the range has been reduced to
about 0.9 meters (2.9 feet). The lack of
alternating flooded and dewatered conditions
at the upper and lower edges of the wetlands
decreased wetland area, resulting in reduced
diversity of plant and wildlife communities.
High sediment loads and excess turbidity have
been noted as stressors in several coastal
wetlands. Sources are site-specific, but are
mostly related to urban and agricultural runoff.
Carp are also a serious problem in Lake
Ontario marshes and shallow water areas
because they resuspend sediments, which
increases turbidity, and they destroy aquatic
macrophytes. Turbidity problems are
compounded by excess nutrients encouraging
rapid algal growth which, in turn, decreases
water clarity and limits the amount of light
reaching rooted plants and the benthic
community. Excess nutrients can also cause
changes in wetland species, reducing the
diversity.
The fish community has improved considerably
from a low point in the 1960s. Alewife and
rainbow smelt abundance declined in the
1980s in response to increased trout and
salmon predation, and to fewer nutrients being
added to the Lake. In the 1990s, stocking of
trout and salmon was reduced to bring them
into better balance with their food supply.
Some native fishes are also recovering from
the low levels observed in the 1960s. For
example, lake whitefish, which typically were
most abundant in the eastern end of the Lake,
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STATE OF THE GREAT LAKES—1997
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were nearly absent in the 1970s, began
increasing in the 1980s, and were 30- to 40-
fold more abundant in the 1990s. And in 1995,
lake trout, which had been eliminated from the
Lake by sea lamprey, habitat loss, and
overfishing, began to reproduce naturally after
an absence of some 45 years.
Seven AOCs have been identified on Lake
Ontario: Eighteenmile Creek, Rochester
Embayment, Oswego River, Bay of Quinte,
Port Hope Harbour, Metro Toronto and Region,
and Hamilton Harbour. Although Buffalo River
technically drains into Lake Erie, it is
considered an additional Lake Ontario AOC
because most of the impacts are in Lake
Ontario. Most of these eight AOCs have
contaminated sediments and restricitions on
fish consumption.
At all locations for which information is
available in Lake Ontario and the Niagara
River, a "limited" consumption advisory is in
effect for lake trout. PCB is the principal
contaminant of concern causing the
consumption advisories, with levels of mirex
and dioxin also of concern in certain locations.
There is good long-term information available
for both PCB and mirex in rainbow trout at the
Ganaraska River, which empties into Lake
Ontario. For both contaminants, concentrations
declined between 1976 and the mid-to-late
1980s, but have shown no clear trend since
then. PCBs declined from 3.9 ppm (parts per
million) in 1976 to 0.65 ppm in 1994. Mirex
concentration dropped from 0.26 ppm in 1976
to 0.06 ppm in 1994. Mean mercury
concentration in walleye in eastern Lake
Ontario varied between 0.19 ppm and 0.43
ppm over the period 1981 to 1994, with no
clear trend over this period.
The most significant land-use change in the
Lake Ontario basin over the past 40 years has
been, and continues to be, the urban
expansion of the Greater Toronto Area. Low
net population growth has been replaced by
suburban expansion, extension of the urban
fringe, and development of adjacent rural
areas.
Lake Ontario's overall nearshore terrestrial
health has been given one of the lowest ratings
of the Great Lakes (see Table 8). All four
indicators used to assess nearshore terrestrial
health have been rated as mixed/deteriorating
or poor. Shoreline species and communities
have been lost and this trend is continuing;
many shoreline processes have been
interrupted by armoring.
8. Connecting Channels
The connecting channels of the Great Lakes
consist of the St. Marys River, the St. Clair
River, Lake St. Clair, the Detroit River, the
Niagara River, and the St. Lawrence River.
They are the vital links between the Lakes,
carrying the surface-water outflow from one
Great Lake to the next and are nearly always
considered "nearshore" by the definition set out
earlier in this report. The whole of Lake St.
Clair is considered nearshore because it is so
shallow (mean depth of 4.4 meters, or 14.4
feet). Connecting channels also have an
important role in the transport of water,
sediments, nutrients, and contaminants.
The nearshore areas of both the Lakes and the
connecting channels are affected by the
impacts of urbanization, industry, and
agriculture; however, connecting channels
have the additional impacts of physical
alterations for shipping, water-level
management, and power generation.
Connecting channels are often the most
heavily used areas within the basin by
humans—such use causing impaired habitat in
all the channels, contaminated sediments in
most, and many other beneficial use
impairments. Therefore, part or all of each
connecting channel has been designated as an
AOC. RAPs are being developed on each
interconnecting channel.
STATE OF THE GREAT LAKES —1997
57
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Table 10. Characteristics of the Great Lakes Connecting Channels
Characteristic
Length (km)
Elevation drop (m)
Average Discharge (rtf/s)
Watershed (km2)
River
St. Marys
River
121
6.7
2,100
2,830
St Clair
River
63
1.5
5,097
3,368
Detroit River
41
1.0
5,210
1,844
Niagara
River
58
99.3
5,692
3,251
St Lawrence
River
150
1.6
7,739
Source: Edsall, T. and M. Charlton. 1997. Nearshore Waters of the Great Lakes. (SOLEC 96 Background Paper)
* International section
A brief description of each of the connecting
channels follows, as well as a discussion on
problems common to all or many of them.
8.1 St, Marys River
The St. Marys River drains Lake Superior into
Lake Huron, dropping 6.7 meters (22 feet)
along its length, mostly along the 1.2 kilometer
(0.75 mile) long St. Marys Rapids in Sault Ste.
Marie. The River itself has several tributaries,
but the water entering from these tributaries is
only a small fraction of the drainage from Lake
Superior. Most of the watershed is forested (95
percent) with the small urban and industrial
areas concentrated in Sault Ste. Marie,
Ontario, and Sault Ste. Marie, Michigan.
The upper river above the St. Marys Rapids
has sandy and rocky shores, the lower river is
bordered by extensive marshes in shallow
areas of the large lakes, bays, and islands.
These wetlands appear in general to be less
affected than other connecting channels
downstream, but dredging, filling, and
sediment contamination have caused site-
specific loss of wetland area along the
shoreline of the city of Sault Ste. Marie,
Ontario.
The entire River has been declared an AOC
because of elevated concentrations of
contaminants in the water, localized
contaminants of the sediments, the presence
of fish tumors, localized impairment of the
benthos, and localized high bacterial counts.
These impacts are especially heavy along the
Canadian shore, downstream of Sault Ste.
Marie, Ontario, to Little Lake St. George.
8.2 St. Clair River
The St. Clair River drains Lake Huron into Lake
St. Clair. It forms an expansive bird-foot delta
with many distribution channels, islands, and
wetlands where it meets the Lake. The delta is
a transitional environment between the River
and the Lake. The River above the delta has
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STATE OF THE GREAT LAKES
1997
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relatively high flows because the channel is
uniform with very few bends or meanders,
dropping only 1.4 meters (4.6 feet) between
Lake Huron and the beginning of the delta. The
natural shoreline has a bank 1.5 to 5 meters
(4.9 to 16.4 feet) high, but most of this
shoreline is now artificial, especially on the
U.S. side. Almost the entire U.S. shoreline and
most of the Canadian shoreline consist of
residential, recreational, and industrial
developments and have been extensively
modified. The River also serves as an
important port.
Several small tributaries drain into the River;
however, the flow in the River comes mainly
from Lake Huron. The drainage basin is mostly
agricultural (69 percent), with urban areas
concentrated in a narrow zone along the River
(the larger centers being Sarnia in Ontario and
Port Huron in Michigan). Industry is
concentrated mainly in the first 14 kilometers
(8.75 miles) of the River between Sarnia and
Corunna, Ontario.
The lack of shoreline complexity, the fast
current, the depth of the River, and wave
forces generated by the passage of large
commercial vessels limit wetland development
along the banks of the River. In fact,
indications show that wetlands are now
uncommon habitats in the St. Clair River above
the delta. The remaining wetlands are
therefore particularly important habitats for
plants, fish, and wildlife in the River.
Wetland and habitat loss in the River appears
to be largely related to extensive bulkheading,
shoreline hardening, filling, channelization, and
dredging along the shores of the River. Urban
encroachment continues to cause wetland loss
and impairment on the Canadian side.
The St. Clair River was declared an AOC as a
result of the levels of toxic substances in the
water, contaminated sediments, impaired
benthos, and bacterial contamination. Industry
is the main source of pollution, but municipal
sewage treatment plants and other point
source and non-point source pollutants are
also concerns. Although progress has been
made in cleaning up the River, impaired
benthos still indicate contaminated sediments
downstream of industrial outfalls, mainly along
the Canadian shoreline.
8.3 Lake St. Clair
Lake St. Clair is a shallow, heart-shaped lake,
1,115 square kilometers (432 square miles) in
area, located between the St. Clair River and
the Detroit River. The maximum natural depth
is only 6.5 meters (21.3 feet), although a
commercial shipping channel has been dug
across the Lake to a depth of 8.5 meters (28
feet). The Lake has a drainage basin of 12,616
square kilometers (4,890 square miles), which
is predominantly agricultural. Tributaries
contribute only 2 percent of the flow to the
Lake, the remainder being from the St. Clair
River.
Lake St. Clair and the St. Clair Delta contain
some of the largest coastal wetlands in the
Great Lakes. Estimates of the extent of these
wetlands vary. The topography surrounding
much of the Lake, especially in the Delta, is
almost flat; therefore water-level fluctuations
greatly affect the extent and position of these
wetlands. Large changes in wetland area are
especially great between years of high and low
water levels. These changes are important for
the diversity of habitat.
On the Canadian side of the St. Clair Delta,
there are at least 12,769 hectares (31,923
acres) of coastal wetlands, a third of which
have been diked for intensive waterfowl
management. On the U.S. side of the delta,
there are around 3,500 hectares (8,750 acres)
of wetlands. Outside the delta, very few
wetlands occur along the highly developed
southern and western shores. Overall, these
wetlands have been reduced by 41 percent
between 1868 and 1973.
STATE OF THE GREAT LAKES —1997
59
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Although most of the U.S. shoreline is now
developed with marinas, urban and cottage
developments, wetland loss from urban and
recreational encroachment continues to be a
problem. Along the Ontario shoreline, much of
the loss results from large-scale conversion of
wetlands to agriculture. More recently, loss has
been caused by agricultural drainage, but
some loss has also resulted from marina and
cottage development. Shoreline development,
dredging and placement of dredge spoils have
also taken their toll on habitat.
Clinton River on the western side of the Lake
has been designated an AOC as a result of
sediment contamination, fish edibility
restrictions, the incidence of tumors in fish,
degraded benthos, elevated phosphorus levels
and bacterial counts, and habitat loss. Most of
these are localized problems. Sources of
pollution include industrial and municipal point
sources, urban and rural non-point sources,
combined sewer overflows, and contaminated
sediments.
8.4 Detroit River
The Detroit River connects Lake St. Clair to
Lake Erie. Around 95 percent of the total flow
in the River enters from Lake St. Clair, and the
remainder flows from tributaries. The Canadian
portion of this watershed is largely agricultural
(90 percent), the remaining area consisting of
urban, residential and industrial lands located
around Windsor in the northern reaches of the
River. The U.S. portion of the watershed is
only 30 percent agricultural, and the remainder
is residential (30 percent), urban (30 percent),
and industrial (10 percent). Over 5 million
people live in the Detroit River watershed.
Eighty-seven percent of the U.S. shoreline and
20 percent of the Canadian shoreline have now
been modified with revetments and other
shoreline hardening structures. Consequently,
many of the historical coastal wetlands have
been lost through dredging, bulkheading, and/
or backfilling. The remaining wetlands mostly
occur on islands in the River. In recent years,
loss of wetlands along the shores has
diminished, but incremental loss from
agricultural conversion, shoreline modification,
marina development, and urban encroachment
is still a concern. Additionally, the shipping
channel is dredged each year for navigation,
substantially changing the River morphology.
The heavy traffic at the port (Detroit is the
busiest port in the Great Lakes), the large
urban areas, and the numerous industries
contribute to the pollution of the River and its
wetlands. The Detroit River and the Rouge
River have both been identified as AOCs.
Sediments in many stretches of the River are
contaminated with heavy metals, oils, and
PCBs, especially along the U.S. side of the
River.
8.5 Niagara River
The Niagara River drains Lake Erie into Lake
Ontario. The River drops close to 100 meters
(328 feet) along its course, most of which is at
Niagara Falls. The natural shoreline of the
River consists of low banks in the upper
portion of the River and a deep gorge cut
through sedimentary deposits in the lower
River below Niagara Falls.
Several tributaries flow into the River from the
U.S. and Canada, but they contribute only a
small fraction of flow to the River. On the
Canadian side, land uses within the watershed
are dominated by agriculture (32 percent),
abandoned agricultural land (23 percent),
urban land (23 percent), and forests (16
percent). On the U.S. side, farmland and
forests are found in the upper parts of the
watershed, but the lower parts are
predominantly urban. Large urban centers
along the River include Fort Erie and Niagara
Falls in Ontario, and Buffalo and Niagara Falls
in New York.
The fast flow of the River has precluded the
development of wetlands in many reaches of
60|
STATE OF THE GREAT LAKES—1997
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the River. Although no specific studies have
been done on wetland loss in the Niagara
River, many wetlands are known to have been
reduced in size or lost. Loss of, and stress to,
wetlands from shoreline modification and
urban encroachment continue to be concerns.
The Niagara River has been declared an AOC
as a result of excessive toxic chemicals in the
water, sediment contamination, fish edibility
restrictions, the incidence of tumors in fish,
degraded benthos, and elevated phosphorus
levels. Sources of pollution include industry
outfalls, sewage treatment plants, other point
sources, and non-point sources. Wetlands
near these sources are vulnerable to
eutrophication and contamination from toxic
chemicals.
8.6 St. Lawrence River
The St. Lawrence River is the outlet of the
Great Lakes system, draining Lake Ontario
and extending 870 kilometers (540 miles) from
the Lake to the Gulf of St. Lawrence. This
report looks at the 186 kilometer (116 mile)
section of the River from Wolfe Island at the
outlet of Lake Ontario to the Quebec border
(this includes the international section of the
River and the Ontario shore of Lake St.
Francis).
Water level and flows have been regulated in
this section of the St. Lawrence River since the
construction of the St. Lawrence Seaway in
1959. Prior to this, the River resembled the
large riverine estuary in the Thousand Island
section. The middle and lower sections down
to Cornwall were part of the riverine system
with many islands and shoals, and many
rapids in the lower reaches of the international
section. The creation of Lake St. Lawrence and
the dredging for navigation and power
production greatly changed the character of
the River and altered these habitats.
The section of the St. Lawrence River
downstream of Cornwall, Ontario, and
Massena, New York, has been declared an
AOC as a result of high levels of toxic
substances in the water, contaminated
sediments, fish consumption advisories,
tumors in fish near Cornwall, degraded
benthos, elevated counts of fecal coliform
bacteria, and eutrophication from elevated
phosphorus downstream of Cornwall.
Bioaccumulation of PCBs has been observed
to be very high in red-winged blackbirds and
tree swallows from coastal wetlands on the
Akwesasne reserve near Cornwall and
Massena.
8.7 Common Stressors of the
Connecting Channels
There are many examples of human-induced
stressors that have an impact on the
ecosystems of the connecting channels,
including erosion from the passage of ships,
dredging and channelization, shoreline
modification, hydroelectric power plants,
excess nutrients, contamination of water and
sediments with toxic chemicals, agricultural
and urban encroachment, and invasive non-
indigenous species.
The effect of the passage of large commercial
vessels on Great Lakes nearshore water
habitat and biota has not been extensively
studied, but the areas of greatest concern are
sections where the vessels follow a dredged
channel that occupies a large portion of the
STATE OF THE GREAT LAKES — 1997
61
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cross-sectional area of the connecting channel.
In these areas, the larger vessels fill much of
the channel and as they pass, they sharply
disrupt the normal water level and flow
conditions. This water movement is believed to
uproot or fragment submerged aquatic plants
and to erode the sediments to which these
plants are attached. A study of the St. Clair
and Detroit Rivers revealed that the density
and diversity of submerged aquatic plants were
lower in the channels used by large
commercial vessels than in the adjacent
channels not used by such vessels. These
effects are even greater during the period of
solid ice cover and can substantially increase
the amount of living plants, decaying plants,
and benthic invertebrates that are swept from
the shallow nearshore portions of the river bed
into the main channel and then moved rapidly
downstream as "drift." The accelerated
transport of this material in winter, when
natural production of aquatic plants and
animals is low, represents a considerable loss
of material and energy that would otherwise be
recycled in summer to provide sustenance to
plants and animals in these portions of the
ecosystem. Commercial and recreational
vessels also cause excess wave action, which
leads to more erosion and more turbidity in
coastal wetlands and other nearshore habitats.
Vessel passage in winter also destroys ice
bridges used by mammals, including wolves
and moose, to cross the St. Marys River; and it
closes natural open pools in the ice field where
bald eagles capture fish in winter. The effects
of vessel passage in winter on the incubation
and survival of lake herring eggs spawned in
the St. Marys River just before ice cover forms
in early winter may be less than previously
thought.
Lake St. Clair, portions of the connecting
channels, and certain other sheltered portions
of the Great Lakes nearshore waters are
important resting and feeding areas for
migrating waterfowl. However, recreational
boaters can flush and otherwise disturb flocks
of resting and feeding birds, causing them to
unnecessarily expend energy needed for
migration, survival, and reproduction. They can
also force them to seek less favorable feeding
and resting habitat or to alter their migratory
schedules. To help relieve this stress,
recreational boating is restricted seasonally in
substantial portions of Lake St. Clair, which
have been declared refuges for migrating
waterfowl.
Urban, recreational, and agricultural
encroachment not only causes habitat and
wetland loss, but also stresses remaining
habitat. In many cases, shoreline hardening
(such as bulkheading and diking) is the
solution to erosion. Where this hardening is
adjacent to remaining wetlands, it restricts their
connection to upland habitats and limits the
landward migration of wetlands during high-
water periods. This causes a backstopping
effect, reducing the size and diversity of
wetland communities. About half the wetlands
in Lake St. Clair and the St. Clair Delta have
been diked. Recreational and urban
developments also fragment the remaining
habitats.
Cottage development produces site-specific
stresses on habitats. These stresses result
from dredging and channelization for boat slips
and mannas and hardening of the shoreline.
Water levels and flows in the Great Lakes and
connecting channels are of considerable
importance for hydroelectric power generation,
for commercial navigation, for recreational
boating, and to owners of residential or
commercial property in low-lying coastal areas.
Water extraction and water-level regulation are
additional stresses to nearshore habitats and
wetlands. Water levels in Lakes Superior and
Ontario and outflows from those Lakes are
regulated by dams in the St. Marys and St.
Lawrence Rivers, respectively. Recent
proposals have been rejected to further
regulate the levels and flows in the system for
the benefit of navigation and hydropower
interests, and to reduce flooding and shoreline
erosion in commercial and residential areas
62
STATE OF THE GREAT LAKES
1997
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during high-water years. The decision not to
regulate the system further expressly
recognized the ecological importance of
retaining the natural fluctuations in levels and
flows in the system.
The most adverse direct ecological effect of
level and flow regulation is felt in coastal
wetlands. These wetlands are adapted to
short-term flooding and draining by storm tides
(seiches) and to seasonal and longer-term
changes (i.e., changes that occur over years or
decades) in lake level, limiting the invasion of
woody vegetation and rejuvenating the wetland
vegetation.
The effect on the fish community of habitat
changes caused by the dams is difficult to
assess because of a lack of pre- and post-
impoundment data. Clearly, however, northern
pike, sunfish, bass, and brown bullhead still
spawn successfully and thrive in the St.
Lawrence River above the dams, while
muskellunge may have declined.
Lake sturgeon have declined, probably through
loss of spawning habitat, blockage of migration
routes, or both. The historical range of lake
sturgeon in New York state waters of the Great
Lakes basin is poorly understood because
exploitation and population decline occurred
before 1950. By that time few lake sturgeon
remained in the St. Lawrence River's
Thousand Islands region; the only self-
sustaining population occurred below the
Moses-Saunders Dam. No fish passage
facilities exist at the Iroquois Dam, which
remains open most of the year; the eel ladder
on the Moses-Saunders Dam is not designed
to pass lake sturgeon. The older dams on all
the major tributaries to the international section
of the St. Lawrence River may have
contributed to the early decline of the area's
lake sturgeon. Efforts are under way to re-
establish lake sturgeon in the U.S. tributaries
to the St. Lawrence River and to assess the
potential for restoring the population in the St.
Lawrence River above and below the Moses-
Saunders Dam.
Walleye were historically common in the St.
Lawrence River, but their numbers declined
sharply after the construction of the St.
Lawrence Seaway and Power Project in 1958,
probably as a result of the inundation of the
rapids and rocky Whitewater areas that were
their preferred spawning habitat. The
population is showing signs of recovery and
abundance has increased irregularly from 1983
to 1993.
The construction (and accompanying dredging
and filling) and operation of dams alter, and
continue to act as stressors on, the local
ecosystems. For example, in Lake St. Francis
on the St. Lawrence River, modifications to the
hydrological regime have resulted in an
increase of 36 centimeters (14 inches) in the
mean water level, and annual water-level
fluctuations no longer occur.
Hydroelectric power generation plants are
located on some of the connecting channels (in
the U.S. and Canadian waters of the St. Marys
River, on the Niagara River, and on the Moses-
Saunders Dam on the St. Lawrence River).
The effects of these particular plants on the
fish community have not been fully assessed;
however, some loss of fish through collision
with turbine blades and other internal surfaces
is inevitable (as discussed in section 6.1). The
extent of the rapids in the St. Marys River has
been substantially reduced because most of
the flow is diverted for power production.
Historically, the rapids supported a productive
fishery for lake whitefish; the remaining rapids
now support a valuable recreational fishery for
stocked trout and salmon. More than half the
flow of the Niagara River is diverted for power
production, causing dewatering of some marsh
areas.
Despite the stresses on the connecting
channels, a wide range of plant, fish, and
wildlife species depends on the nearshore
habitat and wetlands found there. Significant
and rare species of plants can be found in the
wetlands. For example, in Canada the rare
sedge (Carex suberecta) is found only in the
STATE OF THE GREAT LAKES — 1997
63
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coastal wetlands of the Detroit River. Many
species of fish use these habitats either
permanently or temporarily for spawning,
nursery, shelter, or feeding. Lake St. Clair is
one of only two sites in the Great Lakes with
large muskellunge populations. The only large
spawning area for muskellunge left in Lake St.
Clair is in Anchor Bay, Michigan. And the
shallow marshes of the delta are the only
known nursery areas for muskellunge in the
entire St. Clair River, Lake St. Clair, and
Detroit River system. The St. Marys River,
downstream from the dam at Sault Ste. Marie,
and the Niagara River provide spawning
habitat for Pacific salmon and rainbow trout,
which also spawn in many of the tributaries of
the Great Lakes. Several species of reptiles
and amphibians also depend on these
habitats. The only reported site in Ontario for
the northern dusky salamander is in the
Niagara River wetlands.
Many wetlands in the connecting channels
have been identified as significant areas of
waterfowl production, particularly the St. Clair
Delta, which has been identified as one of the
most significant areas for waterfowl production,
staging, and migration in the Great Lakes.
Approximately 16 percent of all the Great
Lakes coastal wetlands of importance to
waterfowl are found in the St. Clair Delta. The
wetlands are important migratory staging areas
and are used as habitat or breeding areas by
other birds (non-waterfowl). Walpole Island
marshes also support the largest number of
nesting pairs of Forster's tern on the Great
Lakes and provide nesting habitat for the black
tern. Even areas that are not important
breeding sites or migration corridors can be
useful to waterfowl when nearby wetlands with
less current, shipping, or thermal pollution are
frozen. Examples of these areas include the
wetlands of the Niagara River, Detroit River,
and St. Clair River.
9. Management Challenges
The fundamental challenge for managers
and decision makers is to understand the
nearshore as an ecosystem and to obtain
enough relevant information to make informed
decisions. Obtaining and communicating such
information is a formidable challenge for
researchers and those responsible for
monitoring the state of the ecosystem.
The SOLEC three-level framework of health,
stressors, and sources (see Figure 3) offers a
way both to organize thinking about the system
and to develop indicators that can be used at
all three levels to define desired states and
measure progress.
Although the ecosystem is complex, an urgent
need exists to agree upon the present state,
desired states, and key steps needed to attain
what is desired. Without agreement on these
issues, rational decision-making or measuring
of progress will be difficult.
The development of community-based
Remedial Action Plans (RAPs) for Areas of
Concern, Lakewide Management Plans
(LaMPs), Fisheries Management Plans, and
various species recovery plans provides an
opportunity to involve the necessary interest
groups and to develop practical plans; but
these planning mechanisms have yet to reach
full potential.
Specific challenges need to be met in the next
two years in the context of the following priority
issues: managing information, integrating
programs, integrating management efforts,
using land efficiently, identifying priority areas
to preserve and protect, and reaching
consensus on indicators.
Information management
The challenge is to bring together available
information on the state of the nearshore
ecosystem into accessible GIS (Geographic
Information System) based formats and
64
STATE OF THE GREAT LAKES—1997
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systems. This is especially the case for living
resources such as plant and other biological
communities; various kinds of coastal
wetlands, including information on quality and
which areas are threatened with loss; and
fisheries, including fish stocks and critical
habitat.
Integration of programs
The challenge is to integrate the concepts of
biodiversity and habitat into existing programs
that, traditionally, are devoted to pollution
control or natural resource management for
harvest.
Integrative management
The challenge is to integrate LaMPs, RAPs,
fisheries management plans, and other
planning activities so that they become fully
viable management mechanisms, useful for
decision makers throughout the Great Lakes
basin ecosystem in taking action and
assessing results.
One of the reasons why consensus on Great
Lakes ecosystem health indicators remains
elusive is that a series of conflicting objectives
and competing agendas have arisen between
the many administrative jurisdictions in the
Great Lakes basin. There are conflicting
opinions about long-term goals for the Great
Lakes. For example, should self-sustaining
food webs be maintained, or should the put-
and-take sport fishery be optimized?; and what
are the most useful ecosystem features to
monitor? Various jurisdictions have competing
mandates, competing time scales, and
competing space scales. The resulting
management challenge involves identifying
ways to improve communication and
cooperation between and within these different
jurisdictions, as well as integrating
management efforts. The challenge of
resolving multiple and sometimes conflicting
goals lies within the general goal of integrative
management.
Efficient land use
The challenge is to find ways to promote land
use that is both efficient and protective of high-
value habitat.
As discussed during SOLEC 96, changing land
use is one of the greatest sources of
ecosystem disruption and loss. Human
population growth in the Great Lakes basin is
expected to continue. The challenge is to find
ways of accommodating this growth and use
the land in ways that sustain both economic
and ecological health. A major step in
accomplishing this is to find examples of
success and share the information.
Priority areas
The challenge is to identify areas of unusual
importance to the health and integrity of the
Great Lakes ecosystem for priority attention.
The authors of the SOLEC 96 paper "Land by
the Lakes" succeeded in using available
information to identify priority land areas that
have exceptional ecological importance.
Twenty "biodiversity investment areas" were
identified (Figure 17). These places present
key opportunities to create large areas that, if
protected, could preserve ecological integrity
and help protect the health of the Great Lakes
ecosystem. The challenge is to build upon this
initial work, refining identification of key land
areas and also identifying key areas in coastal
wetlands and the aquatic nearshore.
Information to support identification of similar
priority areas for coastal wetlands and aquatic
areas will be developed as background
material for SOLEC 98.
Given the findings that existing protection and
restoration programs are inadequate to meet
the continuing stresses to habitat and physical
processes, a conservation strategy for Great
Lakes coastal areas is urgently needed. This
strategy should seek to involve all levels of
governments and other stakeholders, reflect
commitments to biodiversity conservation and
sustainable development, and secure broad
support from Great Lakes citizens. It should
place special emphasis on protecting large
core areas of shoreline habitat within 20
STATE OF THE GREAT LAKES —1997
65
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Biodiversity Investment Areas. The Biodiversity
Investment Areas are clusters of shoreline
areas with exceptional biodiversity values that
present key opportunities to create large
protected areas that will preserve ecological
integrity and, ultimately, help protect the health
of the Great Lakes themselves.
Indicators
The challenge is to develop easily understood
indicators to support an understanding of the
state of the system and to obtain widespread
agreement on what needs to be done to
measure progress.
At present, there is no agreed-upon system or
set of Great Lakes ecosystem indicators that
are monitored and reported on to measure
progress toward achieving the purpose of the
Great Lakes Water Quality Agreement.
Working to reach that consensus is an
important challenge facing ecosystem
management efforts in the Great Lakes basin.
Indicators that everybody agrees on are useful
because they help define the type and amount
of information that needs to be gathered. The
U.S. and Canada have spent billions of dollars
and uncountable hours of work attempting to
reverse the effects of toxic chemical pollution,
overfishing, and habitat destruction. In order to
justify the tax dollars devoted to Great Lakes
environmental issues, environmental
management agencies must be able to
demonstrate the accomplishments of past
programs and, furthermore, to ensure that the
success of future or continuing programs will
be commensurate with the resources
expended. The focus of SOLEC 98 will be on
developing Great Lakes indicators to help
determine the state of the ecosystem health
and on laying the foundation for future
reporting.
66 STATE OF THE GREAT LAKES—1997
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Lake Superior
Highlands/
Isle Royale
Northwestern Lake Superior
'-. .• •-/
'~ .'
-------
00
Figure 16, Great Lakes Areas of Concern: Impairment of Beneficial Uses (as of December 1996 unless otherwise noted)
1JC CRITERIA (19871 IMPAIRED USES
-------
IJC CRITERIA (1987) IMPAIRED USES
Impaired
H Requires Further Assessment
Restored
Not Impaired
NL - Impaired but not attributable to local sources
AA - After additional assessment not impaired
* The status of the beneficial use impairments will be updated by Sept. 1997
* * The full name is Grand Calumet River/Indiana Harbor Ship Canal
to
-------
10. Glossary of Terms
adsorb - Adhere to solid particles.
alvars - Naturally open areas of thin soil over limestone or marble bedrock, which host a distinctive
vegetation community, including a considerable number of rare plants.
anadromous - Fish that spend most of their life in open waters, but then migrate to tributaries to
spawn, e.g., Atlantic salmon.
Area of Concern (AOC) - An area within the Great Lakes basin recognized by the International
Joint Commission where 1 or more of 14 beneficial uses are impaired or where the objectives
of the GLWQA or local environmental standards are not being achieved.
armoring (shoreline hardening) - The installation of artificial shoreline structures designed to
prevent erosion and protect properties from being washed away.
beneficial uses - The 14 uses that, if impaired in an Area of Concern, the Parties to the GLWQA
will strive to restore through the Remedial Action Plan process.
benthic - Occurring at the bottom of a body of water.
bioaccumulation - The accumulation and concentration of certain persistent chemicals from water
or sediment to organisms in a food chain.
biodeposited - Deposited as part of the remains of a dead organism.
biological diversity - The spectrum of life forms and the ecological processes that support and
sustain them. Biological diversity is a complex of four interacting levels: genetic, species,
community, and landscape. "Biodiversity" is the shortened form.
biomagnification - A cumulative increase in the concentration of a persistent substance in suc-
cessively higher trophic levels of the food chain (e.g., from algae to zooplankton to fish to
birds).
body burden - The concentration of contaminants carried in the body.
bogs - Wetlands with no significant inflows or outflows, receiving water primarily from the atmos-
phere.
bulkheading - The placing of a low wall of stones, concrete, or piling to protect a shore from wave
erosion; does not extend out into a lake.
confined disposal facility - A facility providing a contained disposal area for contaminated
sediments removed during dredging operations.
cryptosporidiosis - An illness due to infection with the protozoan Cryptosporidium, which causes
diarrhea, stomach cramps, upset stomach, and fever.
STATE OF THE GREAT LAKES —1997 71
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DDT (dichlorodiphenyltrichloroethane) - A highly toxic, chlorinated hydrocarbon insecticide,
DDT is now banned from use, but residual amounts remain in the aquatic environment from the
long history of its use and environmental persistence.
dieldrin - A highly toxic persistent insecticide.
dune and swale - Dunes (or ridges) that run parallel to a lake and on the ancestral lake bed. The
dunes are dry and sandy; the swales are wetland areas.
ecoregion - Large landscape area defined by climate, physical characteristics, and the plants and
animals that are able to live there.
ecosystem - A biotic community and its abiotic environment, considered together as a unit. Eco-
systems are characterized by a flow of energy that leads to trophic structure and material
cycling.
eutrophication - The process of fertilization that causes high productivity and biomass in an
aquatic ecosystem. Eutrophication can be a natural process or it can be a cultural process
accelerated by an increase of nutrient loading to a lake by human activity.
evapotranspiration - Evaporation of water from soil, and transpiration of water from plants.
exotic species - Non-native plant and animal species.
extirpated - A plant or animal that has been eliminated from a region.
fens - Wetlands that form where alkaline groundwater seeps to the surface.
food chain - A specific nutrient and energy pathway in ecosystems, proceeding from producer to
consumer.
forage fish - Fish that eat plankton as a mainstay of their diet and are consumed by other fish
higher in the food chain.
fry - A recently hatched fish.
global climate change - Alteration of temperature and precipitation patterns throughout the world
caused by human activity.
habitat - The place where an organism lives, including its biotic and abiotic components. Habitat
includes everything an organism needs to survive.
hormone disruption - Certain chemicals may mimic or interfere with hormonal actions; possible
effects include behavioral changes, reproductive abnormalities, altered immune response,
hormonal imbalance, infertility, and tumors in reproductive tissue.
indicator - A measurable feature that singly or in combination provides manageable and scientifi-
cally useful evidence of environmental and ecosystem quality or reliable evidence of trends in
quality.
72 STATE OF THE GREAT LAKES— 1997
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indigenous - Native to a region.
longshore current - A nearshore current that flows parallel to the shore.
macrophytes - Large plants easily visible without a microscope.
malignancies - Cancerous tumors.
marshes - Wetlands dominated by non-woody vegetation that emerges above the soil or water.
neoplasms - Tumorous growths.
non-point source pollution - Source of pollution in which wastes are not released at one specific,
identifiable point but from a number of points that are spread out and difficult to identify and
control, such as surface runoff from precipitation or atmospheric deposition.
PAH (polynuclear aromatic hydrocarbons) - A class of organic compounds formed through
incomplete combustion and that have cancer-producing properties.
Parties - The Governments of Canada and the United States.
PCBs (polychlorinated biphenyls) - A class of toxic organic compounds used in many industrial
applications. PCBs contain one or more atoms of chlorine, are resistant to high temperatures,
and do not break down in the environment. They are also widely distributed in the environment
and food chains.
piscivorous - Fish-eating.
point source pollution - Easily discernable source of pollution such as a factory pipe.
primary consumers - The level of the food chain that first consumes food photosynthesized by
plants.
raptor - A bird of prey.
Remedial Action Plans (RAPs) - Plans that embody a systematic and comprehensive ecosystem
approach to restoring and protecting beneficial uses in Areas of Concern.
revetments - Facings of stone, concrete, or other material to protect the banks of a lake or river
from erosion; usually built at some angle, unlike a bulkhead which is vertical.
runoff - All water flowing through streams and rivers that goes into the lakes.
species - A group of individuals that can interbreed successfully with one another, but not with
members of other groups. Plants and animals are identified as belonging to a given species on
the basis of similar characteristics.
stakeholders - Everyone with an interest or a stake in something.
STATE OF THE GREAT LAKES — 1997
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Photo Credits
AH photographs can be found on the Great Lakes National Program Office home page:
http://www.epa.gov/glnpo/
Page 9: Don Breneman
Page 25: Indiana Dunes National Lakeshore, National Park Service
Page 28: Romy Myszka, USDA Natural Resources Conservation Service
Page 36: Fairport Fisheries Station, Ohio Department of Natural Resources
Page 42: Carole Y. Swinehart, Michigan Sea Grant Extension
Page 47: Superior National Forest, USDA Forest Service
Page 50: David Riecks, Illinois-Indiana Sea Grant
Page 51: Michigan Travel Bureau
Page 52: U.S. Fish and Wildlife Service
Page 53: M. Woodridge Williams, National Park Service
Page 56: Dave Hansen, Minnesota Extension Service
Page 61: Jerry Bielicki, U.S. Army Corps of Engineers
13. SOLEC 96 Background Paper Information
The SOLEC 96 background papers consist of:
Nearshore Waters of the Great Lakes (ISBN 0-662-26031-7),
Coastal Wetlands of the Great Lakes (ISBN 0-662-26032-5),
Land by the Lakes: Nearshore Terrestrial Ecosystems (ISBN 0-662-26033-3),
Impacts of Changing Land Use (ISBN 0-662-26034-1), and
Information and Information Management (ISBN 0-662-26035-X).
The SOLEC 96 background papers may be accessed via the Internet from the SOLEC home page:
http://www.cciw.ca/solec/
Hardcopies may be obtained from the addresses listed at the bottom of page ii.
76 STATE OF THE GREAT LAKES— 1997
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